The WordPress command line interface (WP-CLI in short) is a very powerful tool. Usually used by advanced users, it can also be enormously helpful to users willing to learn a few basic commands.
For example: if a plugin completely breaks your WordPress installation, the easiest way to get it back online is to use WP-CLI to disable the offending plugin. All you need to enter in the command line is:
$ wp plugin deactivate offending-plugin-slug
If you're not sure what the plugin slug is, run:
wp plugin list
And you'll get a simple list of all plugins, specifically their slugs:
WP-CLI is a great tool and it has amazing documentation, so we highly recommend you check it out and learn more about managing WordPress through the command line interface.