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The Computer

14 min read

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).

The parts of a computer systemInput devices such as a keyboard, mouse and microphone send data to the processor, the CPU, which carries out instructions using memory. The results go to output devices such as the monitor, speakers and printer. Storage devices, such as a hard disk, flash drive and the cloud, keep data when the power is off.InputCPUOutputMemory (RAM)Storagekeyboard, mouse,scanner, cameramonitor, printer,speakerhard disk, flash, cloudtemporary workspaceSoftware tells thehardware what to do

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.

HardwareExamples
Input devicesKeyboard, mouse, scanner, microphone, camera, touch screen
ProcessingCPU (central processing unit), motherboard
MemoryRAM (temporary), ROM (permanent start-up instructions)
StorageHard disk, SSD, flash drive, memory card, DVD, cloud
Output devicesMonitor, printer, speakers, projector
SoftwareDescriptionExamples
Operating systemControls the computer and runs other softwareWindows, Android, Linux, macOS
Utility softwareMaintains the computerAntivirus, backup tools
Application softwareDoes a task for the userWord processor, spreadsheet, browser, games
Programming softwareUsed to write programsPython, Java compilers

Units of data

A bit is a single 0 or 1. One character such as “A” takes one byte.
Worked exampleCounting storage

How many photos of 4 MB can a 32 GB flash drive store?

  1. Convert 32 GB to MB.
  2. 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.

Each unit is 1 024 times larger than the one before; here the sizes are in KB.
Try itFile size and storage

Choose the size of a file and the capacity of a drive.

Check yourself Which is an output device?
Check yourself The operating system is
Check yourself 1 byte is

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.
Word Processing