What is an operating system?

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If you buy a computer without an operating system and switch it on it sits and sulks. It is rather like Doctor Frankenstein's creature before the lightning. Computers are extremely stupid. We have to tell them exactly what to do. Some of our instructions are general purpose ones as in the list below. These are all part of an operating system, examples being Windows, Apple OS and ubuntu. When the operating system is in and running we can then run our applications like Word, LibreOffice, Photoshop, Firefox, Dreamweaver and so on.

To be useful a computer's operating system must:

Allow us to put data in at a keyboard or mouse

Store the data in memory

Allow us to give it instructions on what to do (applications)

Run storage devices like video (CD, DVD, BD) drives, magnetic hard drives and solid state drives.

Connect us to peripherals like printers, scanners, tablets and so on

Send data such as text and pictures to a screen

Send sound data to loudspeakers

Connect to other computers and devices in a network

Connect to wide networks such as the Internet

Allow different users to use it securely

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Last edit 26 December 2015