Computing
What are the parts of a computer?
Quick answer
A computer has input devices to put information in, a processor to work on it, memory and storage to keep it, and output devices to show results. Software tells it what to do.
In one sentence
A computer is made of hardware you can touch and software that tells it what to do, and its parts take in information, process it, store it and show the results.
Explained
Every computer, from a laptop to a phone, works in a loop: input, processing, output, with storage in the middle.
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phone
TV
Input devices put information into the computer: a keyboard, a mouse, a touchscreen, a microphone, a camera. Output devices show you the results: a monitor (screen), speakers, headphones, a printer.
The processor or CPU (central processing unit) is a small chip that carries out instructions, billions of times each second. People call it the brain of the computer, but it does only what its instructions tell it. A computer has two kinds of memory:
- RAM (random access memory) is the short-term working space for the programs you are using now. It is fast, but it is emptied when you switch off.
- Storage (a solid-state drive or hard drive) holds your files, photos and programs for the long term, even when the power is off. This is why you save your work.
All the parts are linked on a main circuit board called the motherboard, and a power supply or battery gives them electricity. A fan may cool the processor.
Everything you can touch is hardware. Software is the set of instructions. The operating system, such as Windows, macOS, Android or Linux, manages the hardware and lets you run apps. Without software, a computer is just a box.
Inside, a computer works with only two states, on and off: see binary. People write instructions in a language a computer can follow; see algorithms. When computers are linked, they form networks, which is described in the internet.
Examples
| Part | Job | Type |
|---|---|---|
| Keyboard, mouse | send information in | input |
| Screen, speakers | show or play results | output |
| CPU | carries out instructions | processing |
| RAM | temporary working space | memory |
| SSD or hard drive | long-term file storage | storage |
Common mistakes
- Mixing up memory and storage. RAM is short-term and storage is long-term.
- "The monitor is the computer." It is only an output device.
- "Software is a thing you can touch." It is the instructions.
Quick quiz
Parts of a computer
Check what you know with 4 quick questions.
Question 1 of 4
Which is an input device?
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For grown-ups
Related topics
Algorithm
An algorithm is a precise, step-by-step set of instructions for solving a problem or doing a task. Computers follow algorithms written as code.
Binary
Binary is a number system that uses only two digits, 0 and 1. Computers use binary to store and process all their information.
Online safety
Staying safe online means keeping personal details private, using privacy settings and strong passwords, being kind, and telling a trusted adult if anything worries you.
The internet
The internet is a huge network that links billions of computers and phones around the world, so they can share information. The web, email and video calls all run on it.
Coding
Coding, or programming, means writing instructions in a language a computer understands so it can do a job, like run a game, an app or a website.
Debugging
Debugging means finding and fixing mistakes, called bugs, in an algorithm or a computer program. It is a normal part of coding for everyone.