CompTIA A+	Vendor-neutral entry-level IT certification requiring two exams from the same series: Core 1 (220-1201) and Core 2 (220-1202), V15, launched March 25 2025.  Tip: Treat A+ as the first rung on the CompTIA ladder - Network+ and Security+ build directly on it.  Example: A help desk candidate passes both A+ exams, then studies Network+ for the same job family.
Core 1 (220-1201)	Hardware-focused exam: mobile devices, networking, hardware, virtualization and cloud, and hardware/network troubleshooting. Pass mark 675 on a 900 scale.  Tip: Study the five Core 1 domains in exam-weight order: troubleshooting (28%) and hardware (25%) first.  Example: A candidate drills hardware and troubleshooting because they make up over half of Core 1.
Core 2 (220-1202)	Software-focused exam: operating systems, security, software troubleshooting, operational procedures. Pass mark 700 on a 900 scale.  Tip: OS and security are each 28% of Core 2 - give them the most review time.  Example: Core 2 prep spends equal top weight on Windows administration and security fundamentals.
Same-version rule	Core 1 and Core 2 must be taken from the SAME exam version; mixing exam series (like 220-1101 with 220-1202) is not allowed.  Tip: Before registering for the second exam, confirm both vouchers match the 220-1200 series.  Example: A candidate who started v14 must take both exams in v15 - not one in each.
Mobile device hardware	Laptop and tablet internals: replaceable batteries, cameras, Wi-Fi and Bluetooth antennas, and add-on storage.  Tip: Know which laptop parts are field-serviceable (RAM, storage, battery) versus soldered.  Example: A tech swaps a laptop's M.2 SSD and RAM while the CPU stays soldered to the board.
Battery management	Lithium-ion batteries degrade by charge cycles and heat; calibrate by full discharge only when the vendor asks.  Tip: Keep laptops cool and avoid leaving them at 100% for months to extend battery life.  Example: A fleet of docks runs cool and is charged to 80%, doubling average battery lifespan.
Wi-Fi/Bluetooth antennas	Laptops hide antenna wires along the display bezel for Wi-Fi and Bluetooth signals.  Tip: Reconnect antennas after display work - a loose wire explains a sudden Wi-Fi drop.  Example: After replacing a laptop screen, the tech reseats the two antenna leads and Wi-Fi returns.
TCP vs UDP	TCP is connection-oriented with guaranteed delivery; UDP is fast, connectionless, and loss-tolerant.  Tip: Match the protocol to the job: files need TCP, streaming and VOIP use UDP.  Example: Video call audio runs over UDP so a dropped packet becomes a blip, not a stall.
Port 20/21 - FTP	FTP transfers files on port 21 (control) and 20 (data) in plaintext - no encryption by default.  Tip: Prefer FTPS or SFTP in answers where security matters; port 21 marks plaintext FTP.  Example: A legacy device only supports FTP on port 21, so the tech wraps it in a VPN.
Port 22 - SSH	Secure Shell: encrypted remote administration and secure file transfer (SFTP rides on 22).  Tip: Port 22 is the safe remote-management answer versus plaintext Telnet on 23.  Example: An admin manages a Linux server over SSH from a laptop on the same LAN.
Port 23 - Telnet	Legacy plaintext remote terminal protocol - unencrypted and discouraged.  Tip: Flag Telnet as insecure; any modern answer uses SSH instead.  Example: A router still offers Telnet; the tech disables it and enables SSH.
Router	Forwards packets between networks, serves as the gateway, and usually hosts DHCP and NAT at home or small office.  Tip: Label the router as the gateway-plus-DHCP device in SOHO topology answers.  Example: A home router gives every device an address and sends traffic to the internet.
Switch	Connects devices on the same LAN, forwarding frames by MAC address.  Tip: Switches extend LAN ports; routers move between networks - keep the two separate.  Example: Four desktops plug into a switch that uplinks to the router.
Access point	Bridges wireless clients onto the wired network using SSIDs and encryption.  Tip: In a wireless question, the access point is the device that actually serves Wi-Fi.  Example: An office installs an access point so a conference room gets Wi-Fi coverage.
SOHO network design	Small office/home office topology: modem to router to switch to devices, with wired and wireless segments.  Tip: Draw the flow modem - router - switch - devices to answer topology questions fast.  Example: A home network runs modem gateway router switch, then two PCs wired and phones on Wi-Fi.
Motherboard form factors	ATX, micro-ATX, and mini-ITX define board size, mounting holes, and expansion slots.  Tip: Match the form factor to the case; mini-ITX means fewer slots, not less power.  Example: A small build uses mini-ITX in a compact case with a single PCIe slot.
Chipset	The chipset routes data between CPU, RAM, storage, and peripherals and defines supported features.  Tip: Chipset questions: it manages the motherboard's feature set and connectivity.  Example: A chipset decides how many USB ports and M.2 slots the board can offer.
CPU sockets	Sockets (like LGA) must match the CPU generation; they define pin layout and cooler mounting.  Tip: Match CPU and motherboard by socket - never force a CPU into the wrong socket.  Example: An LGA1700 CPU only fits an LGA1700 board; the tech verifies before installing.
Cores and threads	Cores are physical processing units; threads (Hyper-Threading/SMT) let each core handle two tasks.  Tip: More cores helps multitasking; thread count matters for virtualization workloads.  Example: An 8-core CPU with SMT shows 16 logical processors in the OS.
HDD	Hard disk drives store data on spinning platters; large capacity at low cost, slower, mechanical.  Tip: Choose HDD for bulk archiving; SSD for anything performance-sensitive.  Example: A NAS archives video files on 8 TB HDDs because capacity beats speed there.
SSD	Solid-state drives use NAND flash with no moving parts; fast boots, low power, shock resistant.  Tip: SSD is the default performance answer for OS drives and laptops.  Example: An old laptop gets an SSD, and boot time drops from minutes to seconds.
NVMe and M.2	M.2 is the small card form factor; NVMe is the PCIe-based protocol with very high throughput.  Tip: NVMe/M.2 = fastest storage answer; SATA M.2 exists but is slower.  Example: A new workstation boots from a 1 TB NVMe M.2 drive with multi-gigabyte speeds.
SATA	Serial ATA connects drives at up to 6 Gbps; the common interface for 2.5-inch SSDs and HDDs.  Tip: SATA answers suit mechanical drives and 2.5-inch SSDs; NVMe answers for speed.  Example: A data drive (HDD) and an OS drive (SATA SSD) both connect over SATA ports.
USB generations	USB 2.0 at 480 Mbps, USB 3.x at 5/10/20 Gbps, USB4/Thunderbolt at 40 Gbps; Type-A and Type-C connectors.  Tip: Match USB speed to the peripheral: external SSDs want USB 3.x or newer.  Example: A backup SSD over USB 3.2 runs far faster than the same drive on USB 2.0.
USB-C	Reversible, power-delivery capable, and carries video, data, and charging in one cable.  Tip: USB-C is the modern 'one cable' answer for docking and charging.  Example: A laptop connects to a dock over a single USB-C cable for power, video, and data.
Thunderbolt	Intel/Apple standard over USB-C: up to 40 Gbps, daisy-chaining, and external GPU support.  Tip: Thunderbolt answers pair with 40 Gbps and daisy-chained high-speed devices.  Example: A video editor daisy-chains two 4K monitors from one Thunderbolt port.
HDMI	Digital audio/video port common on TVs and monitors; carries uncompressed video plus audio.  Tip: HDMI is the display answer for TVs and consumer monitors.  Example: A conference TV mirrors a laptop over HDMI.
Virtual machine	A software-emulated computer running its own OS on shared host hardware.  Tip: VM answers: one physical host, many isolated guests.  Example: A server runs Windows and Linux simultaneously in separate VMs.
Hypervisor	Software that creates and runs VMs: Type 1 bare-metal (ESXi, Hyper-V) or Type 2 hosted.  Tip: Type 1 runs directly on hardware; Type 2 runs inside an OS.  Example: A lab uses VirtualBox (Type 2); a production host uses ESXi (Type 1).
Host vs guest	The host is the physical machine running the hypervisor; guests are the VMs inside it.  Tip: Name the physical box host and the VM guest in any virtualization question.  Example: A host crash takes down all of its guest VMs together.
Troubleshooting methodology	Identify the problem, establish a theory, test the theory, plan and implement a fix, verify, document.  Tip: Answers that ask order: identify first, document last.  Example: A no-internet ticket is worked in methodology order and the fix is documented.
Identifying the problem	Gather details: what changed, when it started, error messages, and who is affected.  Tip: Ask the user what changed - it beats guessing nine times out of ten.  Example: A user says the network died 'after the storm,' pointing to a power or modem issue.
Establish a theory	Form a probable cause from symptoms before touching hardware: power, connection, settings.  Tip: Generate multiple theories, then test the cheapest one first.  Example: No link light plus recent storm suggests a dead modem before a bad NIC.
Test the theory	Verify with tools: ping, link lights, cable tester, or swap-in known-good hardware.  Tip: Swapping a known-good cable or device isolates the failing part fast.  Example: A ping fails on a wired PC; replacing the cable restores the link.
Plan and implement	Choose the least invasive fix, back up settings or data, and note rollback steps.  Tip: Prefer configuration fixes before hardware replacements.  Example: The tech reconfigures DNS before ordering a new router.
Windows editions	Home, Pro, Enterprise, and Education differ in features like BitLocker, domain join, and group policy.  Tip: Pro/Enterprise answers carry BitLocker and domain join; Home lacks them.  Example: A business workstation runs Windows 11 Pro to join the domain and use BitLocker.
Windows 11 requirements	Modern CPU, 4 GB RAM minimum, 64 GB storage, UEFI with Secure Boot, and TPM 2.0.  Tip: TPM 2.0 and Secure Boot are the modern install answers.  Example: A PC that fails the Windows 11 check usually lacks TPM 2.0.
Clean install vs upgrade	Clean installs wipe and load fresh; upgrades keep apps and settings in place.  Tip: Choose upgrade to preserve data; clean install for a fresh, consistent image.  Example: A slow Windows 10 PC gets a clean Windows 11 install, losing no work after a backup.
In-place upgrade	Upgrade install keeps user files, apps, and settings while moving to a newer edition or version.  Tip: Answer in-place upgrade when data preservation is required.  Example: A user upgrades Windows 10 to 11 in place and keeps all documents.
Task Manager	Shows processes, performance, startup apps, and lets you end tasks and change priorities.  Tip: Task Manager is the first stop for a slow PC - find the hog.  Example: A runaway process pegs CPU; Task Manager ends it and the PC recovers.
Disk Management	Creates, formats, shrinks, and extends partitions; assigns drive letters; initializes disks.  Tip: Extend a volume only when adjacent unallocated space exists.  Example: A tech extends C: by 50 GB from adjacent unallocated space in Disk Management.
Device Manager	Lists hardware, shows driver status, and updates or rolls back drivers.  Tip: Yellow warning in Device Manager = driver problem; update or roll back there.  Example: A sound device shows an error; rolling back the driver restores audio.
System Configuration (msconfig)	Controls startup items, boot options, and services for troubleshooting.  Tip: Safe boot under msconfig is quick for diagnosis; uncheck it after.  Example: Launching msconfig and selecting Safe Boot loads a minimal Windows.
macOS fundamentals	Unix-based OS with Finder, Dock, System Settings, and Gatekeeper app security.  Tip: macOS answers pair with Gatekeeper, Time Machine, and Spotlight.  Example: A Mac blocks an unsigned app via Gatekeeper until the user allows it.
Time Machine	macOS built-in backup to external drive or network share, with hourly snapshots.  Tip: Time Machine is the macOS backup answer; restore from it after drive failure.  Example: A Mac recovers an accidentally deleted file from Time Machine.
macOS recovery	Command-R boots macOS Recovery for reinstalls, disk utility, and restore.  Tip: Command-R answers: recovery and reinstall without a bootable USB.  Example: A Mac with a failing OS is reinstalled from Recovery.
CIA triad	Confidentiality, Integrity, Availability - the three security goals framing most controls.  Tip: Map controls to the triad in questions: encryption = confidentiality.  Example: Backups support availability; hashes verify integrity; passwords protect confidentiality.
Encryption basics	Symmetric uses one key; asymmetric uses a public/private pair; TLS protects data in transit.  Tip: Encryption answers: at rest - BitLocker/FileVault; in transit - TLS/VPN.  Example: A laptop's drive is encrypted with BitLocker; web traffic uses TLS.
BitLocker	Windows full-disk encryption tied to TPM; requires Pro/Enterprise editions.  Tip: BitLocker pairs with TPM and Pro editions; Home cannot run it.  Example: A stolen Pro laptop yields nothing because BitLocker encrypts the drive.
FileVault	macOS full-disk encryption with FileVault on Apple Silicon or Intel Macs.  Tip: FileVault is the macOS full-disk encryption answer.  Example: A Mac's data stays unreadable without the FileVault recovery key.
Application won't start	Check compatibility, missing dependencies, corrupt files, and permissions; reinstall as last resort.  Tip: Repair install before full reinstall; check the event log for the error.  Example: A legacy app fails until compatibility mode is set on the executable.
Slow application	Causes: low memory, runaway processes, disk pressure, and background activity.  Tip: Close hogs and check disk space before blaming the app itself.  Example: An email client crawls because the disk is 98 percent full.
App crashes and freezes	Use Task Manager to end the task, check the app's logs, and apply the vendor fix or update.  Tip: Record the failure details from Event Viewer for accurate diagnosis.  Example: A video app freezes on export until its GPU driver is updated.
Driver issues	Yellow device errors in Device Manager: update, roll back, or reinstall the matching driver.  Tip: Roll back the last driver change when a device broke right after an update.  Example: A printer fails after a Windows update; rolling back the driver restores it.
ESD protection	Electrostatic discharge damages components; use ESD straps and mats when handling parts.  Tip: Wear the strap and touch the case before touching components.  Example: A tech wearing an ESD strap installs RAM without zapping the board.
Power safety	Unplug before working inside; check for damaged cables and proper grounding.  Tip: Verify power is off and discharged before internal work.  Example: A technician unplugs a PSU and presses power to drain capacitors before service.
Surge and UPS	Surge suppressors and UPSes protect equipment and keep servers up during dips.  Tip: Server and storage gear go on UPS; desktop workstations on surge protectors.  Example: A brief brownout passes without a reboot thanks to the UPS.
Backup types	Full backs up everything; incremental backs up changes since the last backup of any type; differential since the last full.  Tip: Full + incremental saves space; restoring takes full plus all incrementals.  Example: A nightly incremental plus weekly full restores to Wednesday's state with two tapes.
3-2-1 backup rule	Three copies of data, on two different media, with one copy offsite.  Tip: Choose the 3-2-1 answer for resilient backup strategy questions.  Example: A business keeps the NAS copy, an external disk, and a cloud copy.
Cloud backup	Offsite copies in cloud storage protect against fire, theft, and ransomware.  Tip: Cloud backup is the offsite leg of the 3-2-1 rule.  Example: A small firm syncs critical folders to cloud storage nightly.
