A command is a directive to the computer to perform a certain task. There is a set of commands available in every programming language including DCL. An example of a DCL command is DIRECTORY.
A list of DCL commands is available here and in the OpenVMS Help Utility. The following features are provided by DCL:
- command abbreviation: commands can be abbreviated to 4 characters or more
- command normalization: DCL will remove all comments, trailing, leading, and double spaces, and translate all characters to uppercase before accepting the command
Upon accepting a command, the CLI parses it and either executes it or invokes the respective image.