A computer program is a list of instructions that tell a computer what to do. Everything a computer does is done by using a computer program. Programs stored in the memory of a computer ("internal programming") let the computer do one thing after another, even with breaks in between. John von Neumann, a mathematician born in Hungary, came up with this idea in the late 1940s. The first digital computer designed with internal programming capacity was the EDVAC (which means Electronic Discrete Variable Automatic Computer), built in 1949.
Some examples of computer programs:
- Operating system.
- A web browser like Mozilla Firefox and Chrome can be used to view web pages on the Internet.
- An office suite can be used to write documents or spreadsheets.
- Video games are computer programs.
A computer program is stored as a file on the computer's hard drive. When the user runs the program, the file is read by the computer, and the processor reads the data in the file as a list of instructions. Then the computer does what the computer program tells it to do.
A computer program is written by a programmer. It is very difficult to write in the ones and zeroes of machine code, which is what the computer can read, so computer programmers write in a programming language, such as BASIC, C, or Java. Once it is written, the programmer uses a compiler to turn it into a language that the computer can understand.
There are also bad programs, called malware, written by people who want to do bad things to a computer. Some are spyware, trying to steal information from the computer. Some try to damage the data stored on the hard drive. Some others send users to web sites that offer to sell them things. Some are computer viruses or ransomware.
- Computer program Citizendium