The Basics of Computer Hardware

Computer hardware is all the physical components that make up a computer system. The central piece of hardware is the motherboard, which coordinates all other parts of the system.

The Motherboard contains slots for expansion cards, which allow you to add things like a graphics card or sound card. It also has a nonvolatile memory chip called a ROM that holds instructions for “booting” the computer.


The processor is the heart of your computer. It is a silicon chip that sits on the motherboard and acts as your machine’s brain, telling other components like your video card or disk drives what to do.

A computer’s processor can either multitask or handle tasks one at a time, depending on how many cores it has. Generally, single-core processors are best for everyday computing and low-end gaming while quad- or hexa-core processors are able to take on more demanding tasks such as professional video editing.

The processor’s performance is largely determined by its core and clock speed, which tells how many processing steps it can make per second. It also has a cache of memory to store frequently used data. The other defining aspect of a processor is its bus lines, which are electrical data roadways that carry instructions from and to memory.


The memory is the computer’s volatile storage for currently-used data and codes, which is refreshed each time the CPU shuts down. This makes RAM vital to your computer’s functionality and has led to many improvements over the years, including more powerful chips and more efficient ways to manage memory.

Modern memory is made of multiple chips that form memory cells. Each memory chip has a big number called an address, which the CPU sends to get data from a location. But it doesn’t just read a single byte of data at one time; the CPU actually asks to read a burst of several bytes, which is what causes that long wait known as latency. Computers also have hard disk drives (HDDs) and solid-state drives (SSDs) for permanent file storage.

Graphics Card

Graphics cards, also known as GPUs (graphics processing units), are a crucial part of most computers. They offload graphical tasks from the computer’s central processing unit, allowing it to run faster and more efficiently. They also have their own dedicated memory, called video RAM, which holds graphical data and completed images until they’re ready to be displayed on the screen.

Like other specialized computer hardware, graphics cards require a compatible motherboard and power supply unit (PSU), and they also have specific wattages that need to be met. They also tend to be more expensive than other computer components, so choosing one that suits your needs and budget is important.

Hard Drive

Although solid-state drives (SSDs) are becoming the norm, hard disk drives (HDDs) are still used by many computers. They work by carefully coordinated action across multiple electronic and mechanical components to record and retrieve data. When a computer starts up, the hard drive performs an elaborate power-on sequence to check for both mechanical and electrical failures. After a self-check, the microcontroller on the PCB starts recording a data request from the motherboard.

The disk controller interprets the data and tells the actuator arm to move its read/write heads over the platter surfaces. The read/write head flies just above the platters, hovering a few nanometers above them. The HDD stores a translation table that bridges the operating system’s logical addressing with the platters’ physical addressing. The drive also has a service area that stores critical data for error recovery.


The motherboard is the foundation of a computer and where most other components connect. Also referred to as the main board, mboard, mobo or logic board (Apple computers), it allocates power and allows communication between the CPU, RAM and other components.

Motherboards come in different “form factors” to suit their intended use. The most common are ATX, Micro-ATX and Mini-ITX.

A motherboard’s CPU slot houses the actual CPU, which executes instructions specified by desktop programs. It has memory slots for adding extra memory, and PCIe or PCI Express slots for expansion cards like graphics cards. The motherboard also has peripheral connectors for devices such as keyboards and mice. It includes a power supply and a cooling fan to eliminate heat that’s generated as the motherboard uses electricity.