The Basics of Computer Hardware

Computer hardware is all the physical parts that make up a computer. It includes the central processing unit, random access memory (RAM), and the motherboard. It also includes internal disks, a graphical processing unit, and external devices like a mouse and keyboard.

The CPU is a series of chips packaged together on a flat motherboard that plugs into the system case. The motherboard also contains slots for hard drive and LAN adapter cards.


The central processing unit, or CPU, is the brains behind your computer. It calculates and interprets instructions while you work on projects, play games, or run software applications.

Unlike the memory and clock, which are separate components on your motherboard, the CPU is contained within an integrated circuit chip. Its main functions include the control unit and arithmetic-logic unit.

The CPU clock is responsible for generating the timing signals that connect the other components of the CPU. The control unit uses these signals to execute stored program instructions, just like an orchestra conductor. The arithmetic-logic unit contains the electronic circuitry that executes arithmetic and logical operations.


Many people don’t know how a computer works, but it’s an essential part of modern life whether you’re surfing the Web or organizing your family photos. This PCLT article assumes no technical knowledge but explains how the CPU, RAM and disks work in simple terms.

The CPU guides your computer as it processes data, much like a brain guides a body. Its speed is measured in gigahertz (GHz). A faster CPU will perform more quickly than one with a lower GHz rating.

RAM, or random access memory, stores information created by programs so it’s immediately accessible. This volatile memory is cleared when the computer shuts down.


The motherboard is a central hub that connects all the essential parts of the computer. It allows for the CPU, RAM, expansion slots, and other components to interact as a functional unit.

Motherboards come in different forms or “form factors,” which refer to the size and layout of the board. Some of the most common include ATX, Micro-ATX and Mini-ITX.

A motherboard also includes ports to attach peripherals such as a floppy disk drive, optical drives and hard drives via data cables. It also carries the Basic Input/Output System (BIOS) or Unified Extensible Firmware Interface (UEFI). These are necessary for booting up and managing hardware.

Video Card

The video card creates the visuals that you see on your computer monitor. It contains a Graphic Processing Unit (GPU), a digital-to-analog converter, and memory chips that store display data. Video cards are available as both an integrated component or as a discrete external component that slips into the motherboard’s expansion slot.

Modern graphics cards can accelerate 2D and 3D image rendering for web browsers, photo editing programs, and video games. High-end models can also improve performance in CAD design programs. To see what video card you have, open the System Settings in Windows or use a tool like Speccy to view your hardware.

Sound Card

The sound card is a component that, as the name suggests, allows your computer to emit sound. It takes on the specialized task of translating digital bits (the computer’s language of 1’s and 0’s) into quality sound for speakers and microphones.

Sound cards are either built into your motherboard (onboard) or in expansion slots, and interface with the rest of your computer through a device driver and software application. They’re the maestros for all things auditory. They make the music, video and other audio that you play or hear. They also provide input for devices like headphones and speakers. They do this through a process known as Digital-to-Analog conversion.

Network Card

Often called an Ethernet card, network interface cards (NIC) enable your computer to connect to other devices like routers and printers. You can also plug a wired or wireless NIC into a home or office Wi-Fi to connect to the internet.

Whether you’re working with a wired or wireless connection, the NIC handles all of the transmission and encoding that makes communication possible. The NIC also manages the layers of data that get transmitted between the LAN and your PC.

Most modern laptops and desktop computers include an onboard NIC as standard. These NICs offer a range of different connection speeds, such as 10Mbps, 100Mbps and 1Gbps.