A computer is a machine that accepts data as input, processes that data using programs, and outputs the processed data as information. Many computers can store and retrieve information using hard drives. Computers can be connected together to form networks, allowing connected computers to communicate with each other.
The two principal characteristics of a computer are: It responds to a specific instruction set in a well-defined manner and it can execute a prerecorded list of instructions call a program. There are four main processing steps in a computer: inputting, storage, outputting and processing.
Modern computers can do billions of calculations in a second. Being able to calculate many times per second allows modern computers to multitask, which means they can do many different tasks at the same time. Computers do many different jobs where automation is useful. Some examples are controlling traffic lights, vehicle , security systems, washing machines and