Hardware

The physical side of computing: what each component does, how the parts fit together, and how to recognize — and fix — what goes wrong with them.

17 pages 118 glossary terms A+

How to use this topic

The pages start with an overview of a whole computer and then take the components one by one — from the motherboard and processor to storage, power and the devices around the computer. The last pages bring it together: firmware and the boot process, choosing and upgrading components, troubleshooting, and working safely.

Where a number matters — drive capacity, RAID usable space, power budgets, bandwidth — the pages show the calculation, often as a short Python example that prints exactly the result shown. Virtualization, which the A+ exam also covers, is part of the Cloud topic.

Pages marked A+ cover material from the CompTIA A+ exams — mostly Core 1; the safety and environmental procedures are Core 2 material.

Learning path

  1. 01What's Inside a ComputerThe main components of a computer, what each one does, and how they work together from pressing the power button to a running program.BeginnerA+
  2. 02Motherboards and Form FactorsThe board that connects everything: form factors, the chipset, CPU sockets, memory and expansion slots, and the connectors and headers on it.BeginnerA+
  3. 03CPUsHow a processor works: cores and threads, clock speed and cache, x86 versus ARM, sockets, and keeping it cool.BeginnerA+
  4. 04MemoryWhat RAM does and how it differs from storage: DDR generations, channels, speeds, ECC, and laptop versus desktop modules.BeginnerA+
  5. 05StorageWhere data stays when the power is off: hard drives, solid-state drives, SATA and NVMe, M.2, flash media, and how capacity is counted.BeginnerA+
  6. 06RAIDCombining several drives for speed, redundancy or both: RAID 0, 1, 5, 6 and 10, their capacity and fault tolerance, and why RAID is not a backup.IntermediateA+
  7. 07Power Supplies and PowerHow a computer gets its power: the power supply unit, wattage and efficiency, connectors, and protection with surge protectors and UPSs.BeginnerA+
  8. 08Expansion Cards and GraphicsAdding capabilities through PCI Express: generations and lanes, graphics cards versus integrated graphics, and other common cards.IntermediateA+
  9. 09Ports, Connectors and CablesThe connectors on the outside of a computer: USB generations and USB-C, Thunderbolt, video ports, and the adapters between them.BeginnerA+
  10. 10DisplaysHow monitors and screens work: panel types, resolution and pixel density, refresh rate, color and brightness, and connecting several screens.BeginnerA+
  11. 11Peripherals and Input DevicesKeyboards, mice, scanners, webcams and other devices around the computer, how they connect, and what drivers do.BeginnerA+
  12. 12PrintersHow laser, inkjet, thermal, impact and 3D printers work, the laser printing process step by step, and keeping printers running.IntermediateA+
  13. 13Laptops and Mobile DevicesWhat is different inside laptops, tablets and phones: components, what can be replaced or upgraded, batteries, and mobile connectivity.IntermediateA+
  14. 14BIOS, UEFI and the Boot ProcessWhat happens between pressing the power button and seeing the operating system: firmware, POST, boot order, Secure Boot and the TPM.IntermediateA+
  15. 15Choosing and Upgrading ComponentsPutting the pieces together: compatibility, bottlenecks, sizing a system for its job, and upgrading an existing computer.IntermediateA+
  16. 16Hardware TroubleshootingA structured method for hardware problems, the symptoms that point to each component, and the tools technicians use.IntermediateA+
  17. 17Safety and HandlingWorking safely inside computers: electrostatic discharge, electrical and physical safety, and disposing of equipment responsibly.BeginnerA+

Hardware glossary

Short definitions of the terms used in this topic. The full glossary covers every topic.