What Is a Computer?
A computer takes input, processes it and produces output.
About this topic
A computer is an electronic machine that accepts input, processes it according to stored instructions and produces output, and it can store results for later use. This input–process–output–storage model applies to everything from supercomputers to smartphones, game consoles and the chips in cars and washing machines. Computers matter because they can carry out billions of simple steps every second without getting tired or bored.
Computers are general-purpose because a program determines what they do. The same hardware can be a calculator, a music player or a game depending on the software loaded. Inside, everything is represented as binary numbers, patterns of 0s and 1s, which electronic switches called transistors can store and manipulate reliably.
Think of typing a message on a phone: your touch is input, the processor turns it into text, the screen shows output, and the message is saved in storage. A common misconception is that computers are intelligent. They only follow instructions exactly, which is why a tiny error in a program can cause a big failure. Remember that a computer is hardware plus software, and neither is useful alone.
Key ideas
- Input, process, output, storage
- Hardware vs software
- Programs are instructions
Quick check
Use cases: where What Is a Computer? helps
- Homework: review the key idea behind What Is a Computer? before you start a problem set.
- Exam revision: use the quick check to test whether you can recall What Is a Computer? without notes.
- Visual learning: play with the interactive lab to see how What Is a Computer? changes when you adjust its inputs.
- Teaching a friend: explain What Is a Computer? in your own words, then compare your version with the key ideas.
Computing ideas run phones, search engines, games and the wider internet.
Frequently asked questions
What is What Is a Computer??
A computer takes input, processes it and produces output.
What will I learn in What Is a Computer??
Input, process, output, storage. Hardware vs software. Programs are instructions.
Is What Is a Computer? part of Computer Science?
Yes. It is one of 80 Computer Science topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the What Is a Computer? lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study What Is a Computer??
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.