A computer is a machine used to enter information and receive an answer. Basically, that’s all it does.
The common method for entering data is by typing something into a keyboard, or moving a mouse around. The computer then takes this data, plays with it in a pre-determined way and returns an answer on the screen.
A computer uses programs to determine how to play around with the data. For example, if you open up a word processor and type the words “Hello World”, the program will take the keyboard input, and display it directly on the screen.
Inside a standard computer, be it a laptop, desktop or even a mobile phone there are three main elements. The first is the Central Processing Unit (CPU) this does all the clever stuff with the data. It can do countless calculations every second and works tirelessly the minute you switch the machine on.
The second element is the memory. This stores current data such as the program being run, and any data you input as well as data it has fetched to show you. If you compare a computer to a brain, this is the short term memory. It is very fast but not very large.
The third element would be the long term memory. This is usually a hard drive. This type of memory is very slow, but much larger and is used for saving files and storing away data for a later date. The great thing about this type of memory is that it remains in place even after the machine has been switched off.