All interactions are done through the command-line interface.

If you run joomla by itself, help will be displayed showing all available commands. In addition to this, you can run any joomla command with the -h flag to output help about that specific command.

For example, try running joomla site:create -h. The help will output a one sentence synopsis of what the command does as well as a list of all the options the command accepts.

In depth documentation and use cases of all Console commands by namespace: