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CompTIA A+ Core 1 (220-1201) Glossary

Fuad Efendi March 29, 2026 3 min read

Review the A+ Core 1 terms, abbreviations, and high-confusion pairs that show up across hardware, networking, mobile, and troubleshooting questions.

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Use this glossary for rapid recall, not as your main study method. When a term still feels vague after reading the definition, go back to the relevant lesson page and relearn it in context.

Core terms

Term Fast meaning Start here if it still feels fuzzy
APIPA Automatic private address in the 169.254.0.0/16 range that usually signals a DHCP failure path 2.2 Addressing, TCP/IP & SOHO Foundations
Bluetooth Short-range wireless technology used for accessories, headsets, keyboards, and tethered peripherals 1.2 Mobile Ports, Accessories & Docking
DDR Double data rate memory generation such as DDR4 or DDR5 3.1 Motherboards, Firmware, CPUs & Memory
DFU mode Device Firmware Update mode used for deeper iPhone or iPad recovery 1.4 Mobile Device Troubleshooting
DHCP Dynamic Host Configuration Protocol, the service that hands out IP settings automatically 2.2 Addressing, TCP/IP & SOHO Foundations
DNS Domain Name System, which translates hostnames to IP addresses 2.1 Ports, Protocols & Common Services
Hypervisor Software layer that hosts virtual machines 4.1 Virtualization, Hypervisors & Client-Side Labs
M.2 Physical form factor used by some SSDs, Wi-Fi cards, and expansion modules 3.3 Storage Devices, Interfaces & RAID Basics
NFC Near-field communication, a very short-range wireless technology used for pairing and tap actions 1.2 Mobile Ports, Accessories & Docking
NVMe Non-Volatile Memory Express, a high-speed storage protocol usually carried over PCIe 3.3 Storage Devices, Interfaces & RAID Basics
PBQ Performance-based question that asks you to apply support logic, not only definitions FAQ
PoE Power over Ethernet, which sends electrical power over network cabling to devices like APs or cameras 2.4 Network Tools, Cabling & Basic Evidence
RAID Redundant Array of Independent Disks, storage layouts that trade off performance and fault tolerance 3.3 Storage Devices, Interfaces & RAID Basics
SMART Storage health reporting system that surfaces warning signs on drives 3.3 Storage Devices, Interfaces & RAID Basics
SOHO Small office or home office environment 2.2 Addressing, TCP/IP & SOHO Foundations
UEFI Unified Extensible Firmware Interface, the modern firmware environment that replaced older BIOS behavior in many systems 3.1 Motherboards, Firmware, CPUs & Memory
VDI Virtual desktop infrastructure, where desktops run centrally and are delivered to users remotely 4.2 Cloud Models, Thin Clients & VDI Basics
WPS Wi-Fi Protected Setup, a convenience feature that is usually a bad security choice in SOHO setups 2.3 Wireless Standards, Encryption & SOHO Connectivity

Commonly confused pairs

Pair Quick distinction
M.2 vs NVMe M.2 is a form factor; NVMe is a storage protocol
SATA vs NVMe SATA is slower and older; NVMe usually rides over PCIe and is faster
BIOS vs UEFI BIOS is the older firmware model; UEFI is the newer one with richer boot and security features
Snapshot vs backup Snapshot is a short-term state capture; backup is the safer recovery copy
Hotspot vs tethering Hotspot usually shares mobile data as Wi-Fi; tethering can also mean USB or Bluetooth sharing
2.4 GHz vs 5 GHz vs 6 GHz 2.4 reaches farther but crowds easily; 5 and 6 GHz usually give better throughput with shorter range
Ghosting vs streaking Ghosting often points to fuser or drum behavior; streaking often points to toner, drum, or contamination patterns

Fast recall anchors

  • 169.254.x.x usually means a DHCP path problem
  • names fail but IP works usually points to DNS first
  • RAID 10 means redundancy plus strong performance, but it needs more disks
  • WPA3 is better than WPA2, and WEP is not acceptable today
  • Snapshots are not safe substitutes for true backups

Go back to the cheat sheet for fast review or the study plan if you need a more structured prep order.

Cheat Sheet
FAQ