DOS allows you to perform various activities. For example, you can display a list of files or remove unwanted files, and so on. To perform these activities, you must give DOS certain instructions. These instructions are referred to as DOS commands.
At the command prompt, which is C> or A>, depending upon the active drive, you may enter any of the DOS commands. There are different commands for different activities. After you give the command, DOS carries out what it has been asked to perform. This is also referred to as the execution of DOS commands. DOS commands may be classified as directory commands and file commands.