As you may already know all commands that use ‘help’ keyword are related to providing information about the command line possible options.
If you call it you will get the list of all 17 options of the Angular CLI.
As you can see the last options tells us that if you call
ng [command name] --help
you will be notified what are the correct options and syntax. But you need to specify your request while running the command in the project directory. If not you will be notified to change the directory.
Once you’ll be calling the command in the project directory, for example
ng serve -- help
you’ll get the following set of options