Some commands (usually those used most frequently) are bound to key combinations or key sequences, which means that fewer keystrokes are necessary to execute these commands. Other commands must be invoked explicitly, using Extended Command.
It is also possible to execute shell commands from within the editor. See 3.34 Running shell commands.
Extended Command Editor Command
Key sequence: Meta+X
Allows the user to type in a command name explicitly. Any editor command can be invoked in this way, and this is the usual method of invoking a command that is not bound to any key sequence. Any prefix argument is passed to the command that is invoked.
It is not generally necessary to type in the whole of a command to be executed. Completion (using Tab) can be used after the first part of the command has been typed.
Editor User Guide (Macintosh version) - 01 Dec 2021 19:35:09