Computer

Computers are machines made (or grown in some cases) to do tasks involving information processing, storage, and retrieval. Computers can do calculations, break codes and almost any other logical thing.

On Earth, computers were first being developed in the 20th century, and around the 1960s computers were very large, like WOTAN for example. As time progressed, computers were developed and advanced more so that, by the early 21st century, a computer could fit in your lap and do much more than computers of the 1960s.

On a whole, a computer can become linked up with other computers to create an information network, which today exists as the Internet for us. (DW: The War Machines) The thing about computers, however, is that they are "very sophisticated idiots". They do whatever you tell them to at incredible speeds, so if you order it to kill you and then change your mind, it's very hard to stop it from obeying the original order (but it is not impossible). (DW: Robot)

Computers are also used aboard ships, usually referred to as "the ship's computer". Human ships of the 26th century used computers where the crew had to type in messages of what they were planning to do so the computer would know. (DW: Earthshock)

Some computers achieved apparent self-awareness, an example of this being the computer Xoanon. (DW: The Face of Evil) The War Machines were computers as well, and were able to achieve mobility, having been programed by WOTAN. (DW: The War Machines)

The BOSS was a computer that achieved self awareness by connecting with a human mind. After learning that humans illogic was what enabled them to be unique, he ordered Stevens to program these qualities into him. Despite being self aware, he still exhiited many computer like qualities. For example, The Doctor was able to distract him by asking him a paradoxical question.(DW: The Green Death)

Mr Smith is usually refered to as a computer and performs many similar functions although he is actually a xylok. He has the ability to interface with other computers remotely or via the internet.