A computer is an electronic device that manipulates information, or data. It has the ability to store, retrieve, and process data. You can use a computer to type documents, send email, and browse the Web. You can also use it to handle spreadsheets, accounting, database management, presentations, games, and more. OR
In simple words a computer is an electronic device which takes input process it and gives output. which mean when input is put through keyboard, mouse, scanner or any input device, the data is processed and by computer because the input data is raw then the output is given by computer by displaying it on moniter or any source.