100 CompTIA A+ Terms to Know: Build Your IT Foundation

The CompTIA A+ certification is where most IT and cybersecurity careers begin. It covers hardware, software, operating systems, networking, and troubleshooting — and it builds the mental model that every technical path adds on top of.

Most candidates struggle not because the concepts are too complex, but because the vocabulary is unfamiliar. POST. NVMe. NTFS. APIPA. These terms show up on the exam, in job interviews, and on help desk tickets starting day one. Knowing them before you go deep into study saves time and dramatically improves retention.

We made 100 CompTIA A+ Terms to Know as a vocabulary-first resource — a way to build your language layer before the technical detail. Watch it below, then read on to understand the five domains these terms cover.

Why A+ Vocabulary Sets the Foundation

CompTIA A+ spans two exams — Core 1 (1101) and Core 2 (1102) — covering mobile devices, networking, hardware, virtualization, cloud computing, operating systems, security, and troubleshooting. That is a wide surface area. The candidates who pass aren’t the ones who memorized the most facts. They’re the ones who built a mental model of how systems work — and that starts with vocabulary.

When you know what a term means, you can reason through questions you’ve never seen before. When you don’t, you’re guessing. These 100 terms are designed to give you that conceptual foundation before you open a study guide or practice exam.

Five Domains Every A+ Candidate Should Know

The 100 terms in the video map across five core domains that appear on both A+ exams. Understanding the domains — not just individual definitions — is what separates candidates who can apply knowledge from those who can only recite it.

1. Hardware & Components

CPUs, RAM (DDR4 vs. DDR5, DIMM vs. SO-DIMM), storage types (HDD, SSD, NVMe), motherboards, PSUs, form factors (ATX, micro-ATX, ITX), and expansion cards are the physical vocabulary of IT support. A technician who can’t name the components inside a system can’t diagnose hardware failures, order replacement parts, or explain issues clearly to clients or management.

POST — Power-On Self-Test — is the hardware diagnostic that runs every time a system boots. Understanding POST error codes and beep codes is one of the most practical and frequently tested hardware troubleshooting skills in the A+ exam. It also shows up constantly in real help desk work.

2. Operating Systems

A+ tests Windows (heavily), macOS, Linux, and Chrome OS. Key vocabulary includes file systems (NTFS, FAT32, ext4, APFS), command-line tools (ipconfig, ping, netstat, diskpart, sfc), the Windows Registry, Task Manager, Group Policy, and the difference between 32-bit and 64-bit architectures. Understanding how an operating system manages files, users, and processes is foundational to troubleshooting any endpoint issue — which is the majority of help desk work.

3. Networking Fundamentals

IP addressing (IPv4 vs. IPv6), subnetting, DHCP, DNS, default gateways, and common ports (80, 443, 22, 3389, 25) appear across both exams. You don’t need to be a network engineer at the A+ level, but you do need to understand how a device gets an IP address, what happens when DNS resolution fails, and how to use tools like ping and ipconfig to diagnose connectivity problems. The OSI model — all 7 layers — is tested more than most candidates expect.

4. Security Basics

Malware types (virus, worm, ransomware, spyware, Trojan, rootkit), common attack vectors (phishing, man-in-the-middle, brute force, social engineering), and core defenses (MFA, encryption, User Account Control, principle of least privilege, data destruction methods) are tested in Core 2. Security isn’t a separate domain in A+ — it runs through the whole exam. A technician is often the first line of defense at an organization, and the exam reflects that responsibility.

5. Troubleshooting Methodology

CompTIA’s 6-step troubleshooting process — identify the problem, establish a theory, test the theory, establish a plan, implement the solution, document findings — is explicitly tested and practically essential. The professionals who stand out on the job aren’t just the ones who fixed the problem. They’re the ones who documented it so the next person doesn’t start from scratch. This is entry-level professionalism, and A+ tests it directly.

How Cover6 Uses A+ in Our Training

At Cover6, we treat A+ as the vocabulary and mental model layer of IT and cybersecurity careers — not the finish line. The professionals who build lasting technical careers used A+ to understand how systems work, then added Security+, Network+, or role-specific skills on top of that foundation. The certification matters. What it represents matters more.

Whether you’re targeting a help desk role, working toward a SOC analyst position, or just starting in IT, these 100 terms are the building blocks. Watch the full video, bookmark it, share it with someone just getting started — and if you want to keep building, follow along with Cover6 for more vocabulary breakdowns, certification prep, and community events.