A command may refer to any of the following:
1. A command is a word or phrase that, when typed or spoken, causes the computer to perform a certain operation. For example, at an MS-DOS prompt, when typing the "dir" command and pressing Enter, the user would see a listing of directories and files in the current directory.
2. When referring to a programming language, a command is a unique word used to perform a specific operation. For example, "print" is a command used to display text on the screen. Entering and executing the command below prints "Hello World!" to the screen.
print "Hello World!";