Command

1. A word or set of words that, when typed or in some cases spoken, will cause the computer to perform a certain operation. For example, at a MS-DOS prompt when typing "dir" the user would see a listing of files in the current directory.
   
   See our MS-DOS page for a complete listing of MS-DOS commands.
   See our Unix / Linux page for a large listing of various Unix and Linux commands.
   
   
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. As another example, a user may type the below command in their program to print "Hello World!" on the screen when the program is executed.
   
   print "Hello World!";

Also see: Command key, Command Language, Command prompt, Operating system definitions, Programming definitions, Syntax