Performance-Based Question (PBQ)
A simulated hands-on task on the exam, like configuring a setting or cabling a device.
Getting Started: How the Exam Works
Free knowledge base
CompTIA A+ Core 1 (220-1201) — key terms, tricks & tips
Everything from the course in one searchable place: 291 entries. Use it to review before a practice test or look up a word you forgot.
291 results
Scaled score
A converted score (100-900) used instead of raw percent correct to allow for exam version differences.
Getting Started: How the Exam Works
Domain
A major topic category (e.g., Networking) that groups related exam objectives together.
Getting Started: How the Exam Works
Objectives (exam blueprint)
CompTIA's official published list of exact topics and skills the exam can test.
Getting Started: How the Exam Works
Beta/unscored item
An experimental question CompTIA is testing that doesn't count toward your score, indistinguishable from real ones.
Getting Started: How the Exam Works
Pass score (cut score)
The minimum scaled score CompTIA requires to pass a given exam version.
Getting Started: How the Exam Works
Weighting
The approximate percentage of exam questions drawn from each domain.
Getting Started: How the Exam Works
Exam Overview: Structure, Scoring & Objectives
Remember the domains with 'My New Hardware Vacuums Trouble' — Mobile devices, Networking, Hardware, Virtualization/cloud, Troubleshooting.
Getting Started: How the Exam Works
Exam Overview: Structure, Scoring & Objectives
The exam objectives PDF is the definitive source — CompTIA exam questions can only come from what's listed there, so if a topic isn't in the objectives, it won't be tested, and if it is listed, expect at least one question on it.
Getting Started: How the Exam Works
Exam Overview: Structure, Scoring & Objectives
Assuming the exam is graded as a simple percent-correct instead of a scaled score
Getting Started: How the Exam Works
Exam Overview: Structure, Scoring & Objectives
Spending equal study time on every domain instead of following the official weighting
Getting Started: How the Exam Works
Exam Overview: Structure, Scoring & Objectives
Getting stuck too long on a single PBQ and running out of time for easier questions
Getting Started: How the Exam Works
Active recall
A study method of retrieving information from memory without looking at notes.
Getting Started: How the Exam Works
Spaced repetition
Reviewing material at increasing time intervals to strengthen long-term memory.
Getting Started: How the Exam Works
Home lab
Personal hardware or virtual machine setup used to practice IT skills outside of work.
Getting Started: How the Exam Works
Hypervisor
Software that creates and runs virtual machines on a physical computer.
Getting Started: How the Exam Works
Mark for review
An exam feature letting you flag a question to revisit before submitting.
Getting Started: How the Exam Works
Objectives checklist
The official CompTIA list of exam topics used to guide and verify study coverage.
Getting Started: How the Exam Works
Study Strategy: Tools, Labs, and Test-Day Tips
L.E.A.R.N.: Lab it, Explain it, Active-recall it, Repeat it, Note weak spots — the five habits of a strong study cycle.
Getting Started: How the Exam Works
Study Strategy: Tools, Labs, and Test-Day Tips
The exam objectives document itself is a study tool CompTIA publishes for free; the exam draws questions directly from its listed topics, so use it as your master checklist and note which bullet points you have not yet practiced hands-on.
Getting Started: How the Exam Works
Study Strategy: Tools, Labs, and Test-Day Tips
Rereading notes or watching videos on repeat without ever testing yourself with practice questions
Getting Started: How the Exam Works
Study Strategy: Tools, Labs, and Test-Day Tips
Spending all available lab time on favorite topics while ignoring smaller but still testable objectives
Getting Started: How the Exam Works
Study Strategy: Tools, Labs, and Test-Day Tips
Getting stuck on one difficult performance-based question and running out of time for the rest of the exam
Getting Started: How the Exam Works
ZIF connector
Zero insertion force socket with a lifting tab used for fragile ribbon cables in laptops
Mobile Devices
SODIMM
Small outline dual in-line memory module; the compact RAM format used in most laptops
Mobile Devices
M.2 slot
Small edge-connector slot on the motherboard for compact SSDs or wireless cards
Mobile Devices
BGA (Ball Grid Array)
Soldering method that permanently attaches a chip like the CPU to the motherboard
Mobile Devices
Field-replaceable unit (FRU)
A component designed to be swapped by a technician without factory-level tools
Mobile Devices
ESD strap
Wrist strap grounding the technician to prevent electrostatic discharge damage to components
Mobile Devices
Service manual
Manufacturer documentation detailing exact disassembly steps and screw locations for a model
Mobile Devices
Laptop Hardware Replacement & Component Access
POWER-D: Power off, Open panel, Watch for ESD, Extract carefully, Record with photos, Document screw locations.
Mobile Devices
Laptop Hardware Replacement & Component Access
The 220-1201 objectives explicitly list laptop component replacement (battery, keyboard, RAM, storage, wireless card) as testable content—expect scenario questions asking which panel/tool/step comes first, and questions distinguishing field-replaceable parts from soldered ones like CPU or ultrabook RAM.
Mobile Devices
Laptop Hardware Replacement & Component Access
Yanking a ZIF ribbon cable without lifting its locking tab first, tearing the contacts
Mobile Devices
Laptop Hardware Replacement & Component Access
Mixing screws from different panels, causing wrong-length screws to crack the case on reassembly
Mobile Devices
Laptop Hardware Replacement & Component Access
Assuming RAM or storage is upgradeable without checking the service manual, especially on soldered ultrabooks
Mobile Devices
LCD
Liquid Crystal Display; uses a backlight and liquid crystal layer to form images.
Mobile Devices
IPS
In-Plane Switching; an LCD type with wide viewing angles and accurate color.
Mobile Devices
OLED
Organic Light-Emitting Diode; self-emissive pixels, no backlight needed.
Mobile Devices
AMOLED
Active-Matrix OLED; the OLED type used in most modern smartphones.
Mobile Devices
Digitizer
Transparent touch-sensing layer that converts finger/stylus contact into input.
Mobile Devices
Capacitive touch
Touch technology that senses the electrical charge of a finger.
Mobile Devices
Resistive touch
Older touch technology that senses physical pressure; works with any stylus.
Mobile Devices
Burn-in
Permanent ghost image on OLED screens caused by long-term static content.
Mobile Devices
Mobile Display Types and Digitizers
"OLED Owns its Light, LCD Leans on a bulb" — OLED pixels self-emit light, LCD needs a separate backlight bulb.
Mobile Devices
Mobile Display Types and Digitizers
The exam may show a scenario (screen shows image but no touch response, or touch works but screen is blank) and ask you to identify whether the digitizer or the display failed — memorize that image=display, touch=digitizer.
Mobile Devices
Mobile Display Types and Digitizers
Assuming a cracked screen always means the whole unit is dead — the digitizer or display underneath may still work fine
Mobile Devices
Mobile Display Types and Digitizers
Confusing digitizer failure (no touch response) with display failure (no image)
Mobile Devices
Mobile Display Types and Digitizers
Forgetting that OLED has no backlight, so troubleshooting 'flashlight test' for a dim screen only applies to LCD
Mobile Devices
Docking Station
Device that expands a laptop's ports and capabilities beyond what it natively has
Mobile Devices
Port Replicator
Device that duplicates a laptop's existing ports for single-cable convenience
Mobile Devices
Passive Stylus
Pen-like input tool that mimics a finger on a capacitive touchscreen
Mobile Devices
Active Stylus
Digitizer-based pen offering pressure sensitivity and precise input
Mobile Devices
NFC
Near Field Communication; very short-range wireless tech used for tap-to-pair or payments
Mobile Devices
Bluetooth Pairing
Process of linking two wireless devices so they can communicate
Mobile Devices
POS Reader
Point-of-sale peripheral, often USB-C or Bluetooth, that reads payment cards
Mobile Devices
Port Replication
Concept of mirroring a device's built-in ports through an external hub-like accessory
Mobile Devices
Mobile Accessories and Peripherals
DOCK adds, REPLICATOR duplicates — 'Dock = More, Replicator = Mirror.'
Mobile Devices
Mobile Accessories and Peripherals
The exam objectives explicitly list mobile accessories including connection methods, docking stations, port replicators, touch pens, credit card readers, and other peripherals—expect a scenario question asking you to pick the correct accessory or explain dock vs. replicator differences.
Mobile Devices
Mobile Accessories and Peripherals
Confusing a docking station (adds new ports/capabilities) with a port replicator (just duplicates existing ports)
Mobile Devices
Mobile Accessories and Peripherals
Assuming all styluses are the same—forgetting passive vs. active stylus differences
Mobile Devices
Mobile Accessories and Peripherals
Overlooking that wireless accessory problems (Bluetooth/NFC) often need re-pairing, not hardware replacement
Mobile Devices
MDM
Mobile Device Management; software that remotely configures and secures a fleet of mobile devices
Mobile Devices
MAM
Mobile Application Management; manages and secures individual corporate apps and their data
Mobile Devices
BYOD
Bring Your Own Device; employees use personal devices for work
Mobile Devices
COPE
Corporate-Owned, Personally Enabled; company owns device, allows personal use
Mobile Devices
Remote wipe
MDM feature that erases data on a lost or stolen device
Mobile Devices
Tethering
Sharing a mobile device's cellular data connection with another device
Mobile Devices
Exchange ActiveSync
Protocol syncing email, contacts, and calendars while enforcing security policies
Mobile Devices
Mobile Connectivity, MDM, and Data Sync
BCN-G: Bluetooth (close pairing), Cellular (wide data), NFC (near tap), GPS (satellite guide) — remember the radios by their range, closest to farthest: NFC < Bluetooth < Wi-Fi < Cellular < GPS.
Mobile Devices
Mobile Connectivity, MDM, and Data Sync
The 1201 objectives explicitly list wireless connectivity methods (cellular, Wi-Fi, Bluetooth, NFC) and MDM concepts (remote wipe, application/content management, remote backup). Expect scenario questions asking which feature protects a lost device (remote wipe) or which deployment model matches a description (BYOD vs COPE vs CYOD).
Mobile Devices
Mobile Connectivity, MDM, and Data Sync
Confusing MDM (whole device) with MAM (just apps) on exam questions
Mobile Devices
Mobile Connectivity, MDM, and Data Sync
Forgetting that airplane mode disables Bluetooth and Wi-Fi too, not just cellular
Mobile Devices
Mobile Connectivity, MDM, and Data Sync
Assuming BYOD gives IT the same control level as COPE devices
Mobile Devices
TCP
Connection-oriented protocol that guarantees ordered, reliable delivery via a handshake.
Networking
UDP
Connectionless protocol that sends data quickly without delivery guarantees.
Networking
Well-known ports
Port numbers 0-1023 reserved for standard, widely used services.
Networking
Three-way handshake
SYN, SYN-ACK, ACK sequence that establishes a TCP connection.
Networking
Port
A numbered logical endpoint that identifies a specific service on a device.
Networking
SSH
Secure Shell, encrypted remote login and command execution, port 22.
Networking
RDP
Remote Desktop Protocol, allows graphical remote control of a Windows machine, port 3389.
Networking
Firewall port filtering
Blocking or allowing traffic based on port number and protocol rules.
Networking
TCP/UDP Ports, Protocols, and Services
'FTP Sends Silly Telegrams So Digital Horses Post In Real-time': 21-FTP, 22-SSH, 23-Telnet, 25-SMTP, 53-DNS, 67/68-DHCP, 80-HTTP, 110-POP3, 143-IMAP, 443-HTTPS, 3389-RDP.
Networking
TCP/UDP Ports, Protocols, and Services
The 220-1201 exam objectives explicitly list port numbers to memorize (20/21, 22, 23, 25, 53, 67/68, 80, 110, 143, 443, 3389, and others). Expect matching-style questions like 'Which port does SSH use?' Memorize the number, protocol name, and whether it's TCP or UDP.
Networking
TCP/UDP Ports, Protocols, and Services
Confusing TCP and UDP by assuming all network traffic needs a handshake
Networking
TCP/UDP Ports, Protocols, and Services
Mixing up POP3 (110) and IMAP (143) or forgetting IMAP syncs across devices
Networking
TCP/UDP Ports, Protocols, and Services
Forgetting that HTTPS (443) and SSH (22) are the secure replacements for HTTP (80) and Telnet (23)
Networking
SSID
Service Set Identifier; the visible name of a wireless network
Networking
WPA3
Current strongest wireless encryption standard for securing WiFi traffic
Networking
MIMO
Multiple Input Multiple Output; uses multiple antennas to boost speed/range
Networking
QoS
Quality of Service; prioritizes certain network traffic over others
Networking
Guest Network
Isolated WiFi network for visitors, separate from internal devices
Networking
Port Forwarding
Router rule that routes external traffic to a specific internal device
Networking
Channel
A specific frequency sub-band used to reduce wireless interference
Networking
Firmware
Low-level software running the router's operating system and features
Networking
Wireless Standards, SOHO Routers & Configuration
'Big Girls Need Access Constantly Everywhere' = b, g, n, ac, ax, ... (chronological 802.11 letters, memory hook for standard order)
Networking
Wireless Standards, SOHO Routers & Configuration
The exam may test 802.11 standard details (band, speed) and ask you to pick the BEST first security step on a new SOHO router — always choose changing the default admin password before other options.
Networking
Wireless Standards, SOHO Routers & Configuration
Assuming disabling SSID broadcast is real security — it just hides the name, doesn't encrypt anything
Networking
Wireless Standards, SOHO Routers & Configuration
Leaving default router admin credentials unchanged after setup
Networking
Wireless Standards, SOHO Routers & Configuration
Confusing 5GHz's faster speed with better range — it actually has shorter range than 2.4GHz
Networking
IPv4
32-bit address format written in four dotted decimal octets, e.g., 192.168.1.1.
Networking
IPv6
128-bit address format written in eight hexadecimal groups separated by colons.
Networking
Subnet Mask
Value that defines which part of an IP address is network vs. host.
Networking
DHCP
Protocol that automatically assigns IP configuration to devices on a network.
Networking
APIPA
Automatic Private IP Addressing; self-assigned 169.254.x.x address when DHCP fails.
Networking
DNS
Domain Name System; translates human-readable domain names into IP addresses.
Networking
NAT
Network Address Translation; lets multiple private IPs share one public IP.
Networking
Link-local Address
Automatically assigned address (fe80:: for IPv6) usable only on the local segment.
Networking
IP Addressing: IPv4, IPv6, DHCP, and DNS
DORA Discovers, Offers, Requests, and Acknowledges — just like the cartoon explorer finding her way to an address.
Networking
IP Addressing: IPv4, IPv6, DHCP, and DNS
The exam expects you to instantly recognize address ranges by sight: 169.254.x.x = APIPA/DHCP failure, 10.x/172.16-31.x/192.168.x = private, fe80:: = IPv6 link-local. Memorize the DORA sequence and know that DNS failures let you ping by IP but not by name.
Networking
IP Addressing: IPv4, IPv6, DHCP, and DNS
Confusing a DNS failure (can't resolve names) with a full network outage (can't connect at all)
Networking
IP Addressing: IPv4, IPv6, DHCP, and DNS
Assuming a 169.254.x.x address is a normal valid IP instead of a sign DHCP failed
Networking
IP Addressing: IPv4, IPv6, DHCP, and DNS
Thinking private IP addresses like 192.168.x.x can be reached directly from the internet without NAT/port forwarding
Networking
Plenum
Fire-code-rated cable jacket required in air-handling spaces like above drop ceilings.
Networking
T568A/T568B
Two wiring color-code standards for terminating twisted pair Ethernet cable.
Networking
Crossover cable
Cable wired T568A on one end and T568B on the other, connecting like devices directly.
Networking
Loopback plug
Device that loops transmit pins to receive pins to test a port's hardware.
Networking
Single-mode fiber
Fiber optic cable using laser light for long-distance, high-bandwidth transmission.
Networking
Multi-mode fiber
Fiber optic cable using LED light for shorter-distance transmission.
Networking
Punch-down tool
Tool used to press individual wires into a keystone jack or patch panel.
Networking
Tone generator and probe
Tool set used to trace and identify a specific cable within a bundle or wall.
Networking
Cabling, Connectors, and Network Tools
Crimp Connects, Punch Pierces, Tone Traces, Test Tells, Loop Looks inward — each tool's name hints at its job.
Networking
Cabling, Connectors, and Network Tools
Expect image-based identification questions on the exam: you may be shown a photo of an RJ45 vs RJ11 connector, or LC vs SC vs ST fiber connector, and asked to name it. Also memorize which tool fixes which symptom (no signal = tester, can't find the cable = tone/probe, need new connector = crimper).
Networking
Cabling, Connectors, and Network Tools
Confusing RJ45 (Ethernet) with RJ11 (phone) because they look similar at a glance
Networking
Cabling, Connectors, and Network Tools
Installing PVC-jacketed cable in a plenum space, which violates fire code
Networking
Cabling, Connectors, and Network Tools
Assuming crossover cables are still commonly needed, ignoring that auto-MDIX handles this automatically on modern hardware
Networking
LGA
Land Grid Array; socket type (mainly Intel) where pins are on the motherboard socket.
Hardware
PGA
Pin Grid Array; socket type where pins are on the CPU itself.
Hardware
Chipset
Motherboard chip(s) managing data flow between CPU, RAM, storage, and peripherals.
Hardware
Thermal paste
Compound applied between CPU and heatsink to improve heat conduction.
Hardware
Heatsink
Metal component with fins that draws heat away from the CPU.
Hardware
CMOS battery
Small battery that retains BIOS/UEFI settings and system clock when powered off.
Hardware
PCIe
Peripheral Component Interconnect Express; expansion slot standard for GPUs, NICs, and more.
Hardware
Hyper-Threading
Intel technology allowing one physical core to process two instruction threads.
Hardware
Motherboards, CPUs, and Cooling Systems
Socket Says No: if the Socket type doesn't match, Say No to the install — always check LGA vs PGA before buying.
Hardware
Motherboards, CPUs, and Cooling Systems
Exam objective 1201-3.4/3.5 expects you to match CPU socket types (LGA vs PGA) to compatible motherboards and identify cooling components (heatsink, fan, liquid cooling, thermal paste) by function; memorize that socket type is the #1 compatibility factor between CPU and motherboard.
Hardware
Motherboards, CPUs, and Cooling Systems
Forgetting to apply thermal paste (or applying too much/too little) when installing a cooler
Hardware
Motherboards, CPUs, and Cooling Systems
Assuming any CPU fits any motherboard without checking socket and chipset compatibility
Hardware
Motherboards, CPUs, and Cooling Systems
Ignoring dust buildup as a cause of overheating and blaming the CPU itself
Hardware
DDR (Double Data Rate)
Memory technology transferring data twice per clock cycle; DDR3, DDR4, DDR5 are successive generations.
Hardware
ECC (Error-Correcting Code)
Memory technology that detects and corrects single-bit errors, used in servers and workstations.
Hardware
Dual-channel
Memory architecture using two matched RAM modules to double effective memory bandwidth.
Hardware
QVL (Qualified Vendor List)
Motherboard manufacturer's list of tested and compatible RAM modules.
Hardware
PMIC
Power Management IC built onto DDR5 modules to regulate voltage on the module itself.
Hardware
RDIMM
Registered DIMM; adds a register chip to buffer signals for stability in large server memory arrays.
Hardware
RAM Types and Memory Installation
'3-4-5, Pins Stay Alive': DDR3=240 pins, DDR4=288 pins, DDR5=288 pins but different notch — remember the notch, not just the number, tells the true story.
Hardware
RAM Types and Memory Installation
Core 1 exam objective 3.x expects you to identify RAM types by generation (DDR3/DDR4/DDR5), form factor (DIMM vs SODIMM), and feature (ECC vs non-ECC) from descriptions or images, and to know proper installation and troubleshooting steps including ESD precautions and channel configuration.
Hardware
RAM Types and Memory Installation
Assuming DDR4 and DDR5 are interchangeable because both have 288 pins — the notch position differs and they are not compatible
Hardware
RAM Types and Memory Installation
Forcing a module into a slot without aligning the notch, risking bent pins or a cracked slot
Hardware
RAM Types and Memory Installation
Mixing mismatched RAM speeds/capacities across channels and expecting full dual-channel performance
Hardware
SATA III
Third-generation Serial ATA interface with a 6 Gbps theoretical maximum bandwidth.
Hardware
NVMe
A storage protocol designed for flash memory that runs over the PCIe bus for high speed.
Hardware
M.2
A small card-edge form factor slot on motherboards for SSDs, keyed for SATA or PCIe.
Hardware
RAID
Redundant Array of Independent Disks; combines drives for speed, redundancy, or both.
Hardware
Striping
Splitting data across multiple drives to increase read/write speed.
Hardware
Mirroring
Writing identical copies of data to two drives for fault tolerance.
Hardware
Parity
Calculated data stored across drives that allows rebuilding lost data after a failure.
Hardware
Fake RAID
RAID implemented by motherboard firmware/drivers rather than a dedicated hardware controller.
Hardware
Storage Technologies: SATA, NVMe, and RAID
RAID 0-1-5-10: 'Zero protection, One copy, Five needs three, Ten is twice as tough' — 0=none, 1=mirror(2), 5=parity(3+), 10=mirror+stripe(4+).
Hardware
Storage Technologies: SATA, NVMe, and RAID
Expect direct questions matching a RAID number (0, 1, 5, 10) to its minimum drive count and fault-tolerance behavior, and questions asking you to identify NVMe vs SATA by describing the PCIe bus or M.2 slot. Memorize: RAID 0=speed/no redundancy, RAID 1=mirror/2 drives, RAID 5=parity/3+ drives survives 1 failure, RAID 10=mirror+stripe/4+ drives.
Hardware
Storage Technologies: SATA, NVMe, and RAID
Assuming any M.2 drive fits any M.2 slot without checking keying (B-key vs M-key) and PCIe/SATA support
Hardware
Storage Technologies: SATA, NVMe, and RAID
Confusing RAID 0 (speed, no redundancy) with RAID 1 (redundancy, no speed gain) on exam questions
Hardware
Storage Technologies: SATA, NVMe, and RAID
Forgetting that NVMe is a protocol over PCIe, not a physical connector, while M.2 is the physical form factor
Hardware
ATX
Standard desktop PSU and motherboard form factor defining size and connector layout
Hardware
80 PLUS certification
Rating system indicating PSU energy efficiency at various load levels
Hardware
EPS connector
4-pin or 8-pin connector delivering dedicated power to the CPU
Hardware
Modular PSU
Power supply allowing detachable cables for only the connections needed
Hardware
Thunderbolt
High-bandwidth interface, often USB-C shaped, for fast storage and displays
Hardware
Power Delivery (PD)
USB-C standard enabling higher wattage charging and power negotiation
Hardware
Wattage headroom
Extra PSU capacity beyond calculated load to handle spikes and upgrades
Hardware
Power Supplies and Peripheral Devices
'24 for the board, 8 for the brain (CPU), 6-or-8 for the game (GPU)' — remembers which connector powers what.
Hardware
Power Supplies and Peripheral Devices
Core 1 objective 3.x expects you to identify PSU connector types by name and pin count (24-pin, 4/8-pin EPS, PCIe 6/8-pin, SATA, Molex) and match peripheral connector types (USB-A/C, Thunderbolt, PS/2) to their use cases — memorize connector names and shapes, not just concepts.
Hardware
Power Supplies and Peripheral Devices
Choosing a PSU based only on price and ignoring wattage/connector requirements
Hardware
Power Supplies and Peripheral Devices
Opening a PSU casing to inspect or repair it, risking capacitor shock
Hardware
Power Supplies and Peripheral Devices
Hot-plugging PS/2 devices, which can damage the port or motherboard
Hardware
Fuser Assembly
Heated rollers that melt and bond toner permanently onto paper.
Hardware
Transfer Roller
Component that moves toner from the drum onto the paper.
Hardware
Imaging Drum
Light-sensitive cylinder that holds the latent and toner image.
Hardware
Corona Wire
Wire/roller that applies electrical charge to the drum or paper.
Hardware
Duplexing Assembly
Mechanism that flips paper to print on both sides automatically.
Hardware
Print Head
Inkjet component that sprays ink droplets onto paper through nozzles.
Hardware
Maintenance Kit
Set of replacement parts (rollers, fuser) installed at set page intervals.
Hardware
Printer Technologies and Maintenance
Pretty Cats Eat Dinner, Then Fall Clean — Processing, Charging, Exposing, Developing, Transferring, Fusing, Cleaning.
Hardware
Printer Technologies and Maintenance
The exam frequently tests the exact order of the seven laser imaging steps (Processing, Charging, Exposing, Developing, Transferring, Fusing, Cleaning) — expect drag-and-drop or ordering-style questions on this sequence.
Hardware
Printer Technologies and Maintenance
Confusing the order of Charging and Exposing steps in the laser process
Hardware
Printer Technologies and Maintenance
Assuming all faded print issues are caused by the fuser instead of checking toner or drum first
Hardware
Printer Technologies and Maintenance
Forgetting that thermal printers need no ink or toner, only special paper
Hardware
Type 1 Hypervisor
Bare-metal hypervisor installed directly on hardware with no host OS.
Virtualization and Cloud Computing
Type 2 Hypervisor
Hosted hypervisor that runs as an application on top of an existing OS.
Virtualization and Cloud Computing
Host OS
The base operating system on which a Type 2 hypervisor is installed.
Virtualization and Cloud Computing
Guest OS
The operating system running inside a virtual machine.
Virtualization and Cloud Computing
Bare Metal
Physical hardware with no operating system layer between it and the hypervisor.
Virtualization and Cloud Computing
VMware ESXi
A widely used enterprise Type 1 bare-metal hypervisor.
Virtualization and Cloud Computing
VirtualBox
A free, popular Type 2 hosted hypervisor from Oracle for desktop use.
Virtualization and Cloud Computing
Hypervisors: Type 1 and Type 2 Fundamentals
Type 1 = 'ONE layer' (hardware then hypervisor); Type 2 = 'TWO layers' (hardware, host OS, then hypervisor).
Virtualization and Cloud Computing
Hypervisors: Type 1 and Type 2 Fundamentals
The exam frequently tests direct recall: match 'ESXi' and 'Hyper-V' to Type 1, and 'VirtualBox' and 'Workstation/Fusion' to Type 2. Watch for wording like 'runs on bare metal' (Type 1) versus 'runs on top of an OS' (Type 2).
Virtualization and Cloud Computing
Hypervisors: Type 1 and Type 2 Fundamentals
Thinking Type 2 hypervisors are used in data centers instead of Type 1
Virtualization and Cloud Computing
Hypervisors: Type 1 and Type 2 Fundamentals
Confusing which hypervisor requires a host OS to already be installed
Virtualization and Cloud Computing
Hypervisors: Type 1 and Type 2 Fundamentals
Assuming all hypervisor types perform equally well; Type 1 is faster since there's no host OS overhead
Virtualization and Cloud Computing
vCPU
A virtual CPU core assigned to a guest VM, mapped to physical host processor resources.
Virtualization and Cloud Computing
Oversubscription
Allocating more virtual resources to VMs than the host physically possesses.
Virtualization and Cloud Computing
Resource contention
Performance conflict when multiple VMs compete for the same limited host resource.
Virtualization and Cloud Computing
Ballooning
A hypervisor technique that reclaims unused RAM from one VM to give to another.
Virtualization and Cloud Computing
VM sprawl
Uncontrolled growth of unused or forgotten virtual machines consuming host resources.
Virtualization and Cloud Computing
Hypervisor security
Protecting the virtualization layer since its compromise affects all hosted guest VMs.
Virtualization and Cloud Computing
Capacity planning
Forecasting future resource needs to ensure hosts can support planned VM growth.
Virtualization and Cloud Computing
VM Requirements and Resource Planning
CRISP planning: CPU, RAM, I/O storage, Security, Ports(network) — the five things every VM needs sized right.
Virtualization and Cloud Computing
VM Requirements and Resource Planning
The exam may present a scenario asking what resources to check before deploying a VM (CPU, RAM, storage, network) or ask you to identify a security risk unique to virtualization (hypervisor compromise, VM sprawl). Memorize that resource requirements should match vendor minimums plus growth headroom.
Virtualization and Cloud Computing
VM Requirements and Resource Planning
Allocating resources based on guesswork instead of vendor-published minimum requirements
Virtualization and Cloud Computing
VM Requirements and Resource Planning
Ignoring oversubscription monitoring, leading to host-wide performance degradation
Virtualization and Cloud Computing
VM Requirements and Resource Planning
Leaving unused VMs running, causing VM sprawl and unpatched security exposure
Virtualization and Cloud Computing
SaaS
Software as a Service; a complete application delivered and managed entirely by the provider.
Virtualization and Cloud Computing
PaaS
Platform as a Service; provider manages OS/runtime, customer deploys and manages applications.
Virtualization and Cloud Computing
IaaS
Infrastructure as a Service; provider supplies virtualized hardware, customer manages OS upward.
Virtualization and Cloud Computing
Public cloud
Shared, multi-tenant cloud infrastructure owned and operated by a third-party provider.
Virtualization and Cloud Computing
Private cloud
Cloud infrastructure dedicated to a single organization for greater control and compliance.
Virtualization and Cloud Computing
Hybrid cloud
A combination of public and private clouds with integration allowing workload/data movement.
Virtualization and Cloud Computing
Community cloud
Cloud infrastructure shared by organizations with common regulatory or business needs.
Virtualization and Cloud Computing
Shared responsibility model
Framework defining which security/management tasks belong to the provider versus the customer.
Virtualization and Cloud Computing
Cloud Service and Deployment Models
SPI climbs the stack: Software, Platform, Infrastructure - the higher the letter appears (S is top), the less you manage yourself.
Virtualization and Cloud Computing
Cloud Service and Deployment Models
Exam objective 4.1 explicitly lists SaaS, IaaS, PaaS, and public/private/hybrid/community models as terms you must define and match to scenarios; expect a matching or scenario-based question naming a real product (like Office 365 or AWS EC2) and asking you to classify its service model.
Virtualization and Cloud Computing
Cloud Service and Deployment Models
Confusing PaaS and IaaS by forgetting that PaaS customers never touch the OS, only their application code
Virtualization and Cloud Computing
Cloud Service and Deployment Models
Assuming 'private cloud' must be on-premises; it can be hosted off-site by a provider but dedicated to one company
Virtualization and Cloud Computing
Cloud Service and Deployment Models
Thinking hybrid cloud just means 'using two providers' rather than integrating public and private environments
Virtualization and Cloud Computing
VDI (Virtual Desktop Infrastructure)
Hosting desktop operating systems centrally and delivering them to thin clients over the network.
Virtualization and Cloud Computing
Thin client
A low-power endpoint device with minimal local resources that displays a remote VDI session.
Virtualization and Cloud Computing
Container
A lightweight package of an app and its dependencies sharing the host OS kernel.
Virtualization and Cloud Computing
Container engine
Software like Docker that creates, runs, and manages containers on a host.
Virtualization and Cloud Computing
Elasticity
Cloud's ability to automatically scale resources up or down based on real-time demand.
Virtualization and Cloud Computing
Horizontal scaling
Adding more servers/instances to handle increased load.
Virtualization and Cloud Computing
Vertical scaling
Increasing resources (CPU, RAM) on an existing server.
Virtualization and Cloud Computing
Kernel sharing
Multiple containers using one host operating system kernel instead of separate guest OSes.
Virtualization and Cloud Computing
VDI, Containers, and Cloud Elasticity
VDI = Very Distant desktop, Images live on the server, not your desk. Containers = Carry-on luggage: light, fast, shares the plane's (kernel's) cabin.
Virtualization and Cloud Computing
VDI, Containers, and Cloud Elasticity
Exam objective 4.1 covers cloud concepts including rapid elasticity, and objective 4.2 covers virtualization including VDI purpose. Expect a scenario question asking why a company would choose VDI (centralized control/security) versus a question defining elasticity as automatic scaling based on demand.
Virtualization and Cloud Computing
VDI, Containers, and Cloud Elasticity
Confusing containers with full VMs — containers don't run their own guest OS kernel
Virtualization and Cloud Computing
VDI, Containers, and Cloud Elasticity
Thinking VDI works fine without network connectivity — it fully depends on a live connection to the host
Virtualization and Cloud Computing
VDI, Containers, and Cloud Elasticity
Assuming elasticity means manually adding servers rather than automatic, demand-based scaling
Virtualization and Cloud Computing
Probable cause
The most likely explanation for a symptom, based on initial questioning and evidence, not yet confirmed.
Hardware and Network Troubleshooting
Escalation
Passing a ticket to a more experienced technician when your theory is not confirmed or is beyond your scope.
Hardware and Network Troubleshooting
Root cause
The underlying reason a problem occurred, as opposed to just the visible symptom.
Hardware and Network Troubleshooting
Preventive measures
Actions taken after a fix to reduce the chance the same problem happens again.
Hardware and Network Troubleshooting
Full system functionality
Confirmation that the original issue is resolved and no new issues were introduced.
Hardware and Network Troubleshooting
Knowledge base
A documented collection of past problems and solutions used to speed up future troubleshooting.
Hardware and Network Troubleshooting
Backup before changes
Saving user data or system state before attempting risky fixes, part of Step 1.
Hardware and Network Troubleshooting
CompTIA Troubleshooting Methodology Steps
I Eat Tacos, Please Verify Dinner — Identify, Establish theory, Test theory, Plan/implement, Verify, Document.
Hardware and Network Troubleshooting
CompTIA Troubleshooting Methodology Steps
CompTIA exam questions often present a scenario and ask 'what is the NEXT step' — memorize the exact order (Identify, Theory, Test, Plan/Implement, Verify, Document) because answer choices are designed to tempt you into skipping ahead, such as choosing 'implement the fix' before 'test the theory' is listed as complete.
Hardware and Network Troubleshooting
CompTIA Troubleshooting Methodology Steps
Jumping to a fix or replacing parts before testing the theory of probable cause
Hardware and Network Troubleshooting
CompTIA Troubleshooting Methodology Steps
Closing the ticket without verifying full system functionality, causing repeat calls
Hardware and Network Troubleshooting
CompTIA Troubleshooting Methodology Steps
Skipping documentation, which loses valuable knowledge for future tickets
Hardware and Network Troubleshooting
POST
Power-On Self-Test; firmware routine that checks essential hardware before the OS loads.
Hardware and Network Troubleshooting
UEFI/BIOS
Firmware stored on the motherboard that runs POST and initializes hardware at startup.
Hardware and Network Troubleshooting
Beep code
Pattern of speaker beeps used by firmware to report a POST failure when video isn't available.
Hardware and Network Troubleshooting
POST diagnostic LED/code
Onboard lights or two-digit display showing which POST stage failed.
Hardware and Network Troubleshooting
Boot loader
Software that runs after POST succeeds and locates/starts the operating system.
Hardware and Network Troubleshooting
CMOS
Battery-backed memory storing BIOS/UEFI settings; clearing it resets firmware to defaults.
Hardware and Network Troubleshooting
Minimal configuration troubleshooting
Removing nonessential hardware to isolate which component is preventing a successful boot.
Hardware and Network Troubleshooting
Diagnosing POST and Boot Failures
POST = Power On, Self Test — think 'Prove Our System Turns on' before Windows ever gets a chance to run.
Hardware and Network Troubleshooting
Diagnosing POST and Boot Failures
The exam may show a scenario (no video, beep code, blank screen after power-on) and ask you to identify whether the issue is POST-related and the most likely next troubleshooting step. Remember: no BIOS splash = POST failure = hardware; BIOS splash appears but OS won't load = boot failure = storage/software.
Hardware and Network Troubleshooting
Diagnosing POST and Boot Failures
Assuming any 'won't turn on' complaint is a power supply problem without checking power connector seating first
Hardware and Network Troubleshooting
Diagnosing POST and Boot Failures
Trying to look up a universal beep code chart instead of checking the specific motherboard/BIOS vendor's documentation
Hardware and Network Troubleshooting
Diagnosing POST and Boot Failures
Confusing a POST failure with a boot failure and reinstalling Windows when the real problem is a loose RAM stick
Hardware and Network Troubleshooting
S.M.A.R.T.
Built-in drive monitoring system that predicts failures before they happen.
Hardware and Network Troubleshooting
Degraded array
A RAID array still operating but missing redundancy after a disk failure.
Hardware and Network Troubleshooting
CHKDSK
Windows utility that scans and repairs file system and disk errors.
Hardware and Network Troubleshooting
Rebuild
Process of reconstructing data onto a replacement disk in a RAID array.
Hardware and Network Troubleshooting
Storage and RAID Failure Troubleshooting
RAID 0 = zero protection; RAID 1 = one-to-one mirror; RAID 5 = five-finger parity spread across disks; RAID 10 = ten times tougher (mirror + stripe).
Hardware and Network Troubleshooting
Storage and RAID Failure Troubleshooting
The exam expects you to match RAID levels to fault tolerance and minimum disk counts (RAID 0=no tolerance, RAID 1=mirror/2 disks, RAID 5=parity/3+ disks, RAID 10=mirror+stripe/4+ disks) and to recognize S.M.A.R.T. as the tool that predicts drive failure before data loss.
Hardware and Network Troubleshooting
Storage and RAID Failure Troubleshooting
Assuming a degraded RAID array means all data is already lost
Hardware and Network Troubleshooting
Storage and RAID Failure Troubleshooting
Pulling a live drive from an array to test it instead of checking status first
Hardware and Network Troubleshooting
Storage and RAID Failure Troubleshooting
Ignoring early S.M.A.R.T. warnings and waiting for total failure before backing up
Hardware and Network Troubleshooting
Inverter
A component that converts DC power to the AC needed by CCFL backlights on older LCDs.
Hardware and Network Troubleshooting
Backlight
The light source behind an LCD panel that illuminates the display.
Hardware and Network Troubleshooting
Ghost touch
Unintended touch input registered by a screen without user contact.
Hardware and Network Troubleshooting
Battery swelling
Expansion of a lithium battery due to gas buildup, a fire/safety hazard.
Hardware and Network Troubleshooting
Dead pixel
A pixel that never lights up or is always stuck on one color.
Hardware and Network Troubleshooting
Thermal throttling
A device intentionally slowing performance to reduce heat and prevent damage.
Hardware and Network Troubleshooting
Display and Mobile Device Troubleshooting
D.I.G.-it: Digitizer = touch Input, Glass = image — separate layers, separate failures.
Hardware and Network Troubleshooting
Display and Mobile Device Troubleshooting
The exam tests flashlight-test logic for backlight/inverter failures and expects you to know digitizer vs. screen symptoms; also expect a question on safe handling of a swollen battery (stop charging, don't puncture, recycle properly).
Hardware and Network Troubleshooting
Display and Mobile Device Troubleshooting
Replacing the entire screen assembly when only the backlight or inverter has failed
Hardware and Network Troubleshooting
Display and Mobile Device Troubleshooting
Assuming a cracked screen always means the digitizer is broken (sometimes only the glass or LCD is affected)
Hardware and Network Troubleshooting
Display and Mobile Device Troubleshooting
Continuing to charge or use a device with a visibly swollen battery
Hardware and Network Troubleshooting
Print Spooler
Windows service that queues and manages print jobs before sending them to the printer.
Hardware and Network Troubleshooting
DHCP Reservation
A configuration that always assigns the same IP address to a specific device's MAC address.
Hardware and Network Troubleshooting
Link Light
LED on a NIC or switch port indicating physical connection status.
Hardware and Network Troubleshooting
ping
Command-line tool that tests basic network reachability between two hosts.
Hardware and Network Troubleshooting
tracert
Command-line tool that shows each router hop between source and destination to locate failures.
Hardware and Network Troubleshooting
Fuser
Laser printer component that melts and bonds toner to paper using heat and pressure.
Hardware and Network Troubleshooting
Printer and Network Connectivity Troubleshooting
Physical, Address, Path, Print — PAPP: check the cable, check the IP, check the path, then check the print queue.
Hardware and Network Troubleshooting
Printer and Network Connectivity Troubleshooting
The exam frequently tests recognizing an APIPA (169.254.x.x) address as a DHCP failure symptom, and expects you to know the correct order: check physical connection, then IP config, then local ping, then remote ping/tracert. Also expect a scenario question about restarting the Print Spooler service to clear a stuck queue.
Hardware and Network Troubleshooting
Printer and Network Connectivity Troubleshooting
Replacing a printer or NIC before checking cables, link lights, and driver/spooler status
Hardware and Network Troubleshooting
Printer and Network Connectivity Troubleshooting
Assuming a wireless password issue when the real problem is a wrong security type (WPA2 vs WPA3) or wrong band
Hardware and Network Troubleshooting
Printer and Network Connectivity Troubleshooting
Not setting a DHCP reservation for network printers, causing repeated 'offline' complaints after address changes
Hardware and Network Troubleshooting