What is a computer?
A computer is an electronic device that accepts input, processes it by following instructions, stores the data and gives output. It works with data in binary, using only 0 and 1. Computers are fast, accurate, can store large amounts of data and never get tired; but they cannot think for themselves and need instructions (a program).
Hardware and software
Hardware is the physical parts of a computer you can touch; software is the programs that tell the hardware what to do.
| Hardware | Examples |
|---|---|
| Input devices | Keyboard, mouse, scanner, microphone, camera, touch screen |
| Processing | CPU (central processing unit), motherboard |
| Memory | RAM (temporary), ROM (permanent start-up instructions) |
| Storage | Hard disk, SSD, flash drive, memory card, DVD, cloud |
| Output devices | Monitor, printer, speakers, projector |
| Software | Description | Examples |
|---|---|---|
| Operating system | Controls the computer and runs other software | Windows, Android, Linux, macOS |
| Utility software | Maintains the computer | Antivirus, backup tools |
| Application software | Does a task for the user | Word processor, spreadsheet, browser, games |
| Programming software | Used to write programs | Python, Java compilers |
Units of data
How many photos of 4 MB can a 32 GB flash drive store?
- Convert 32 GB to MB.
- Divide.
Answer: About 8 192 photos.
Connecting peripherals and the Internet
Peripherals connect by USB, HDMI (video), audio jacks, Bluetooth and Wi-Fi. To connect to the Internet you need a device, a modem and router (or mobile data), and an Internet service provider (ISP). Wi-Fi is wireless; Ethernet is a cable. Always keep the computer clean, protected by an antivirus, and shut it down correctly.
Choose the size of a file and the capacity of a drive.
Key terms
- Hardware
- The physical parts of a computer.
- Software
- Programs that run on a computer.
- CPU
- Central processing unit, the “brain” of the computer.
- Byte
- A group of eight bits.
Summary
- A computer takes input, processes, stores and outputs data.
- Hardware is physical; software is the programs.
- 1 byte = 8 bits and each unit up is 1 024 times larger.
- Peripherals connect through USB, HDMI, Bluetooth and Wi-Fi.