As Terry Lambert, the developer behind Linux ancestor Unix, once said, "It is not Unix's job to stop you from shooting your foot. If you so choose to do so, then it is Unix's job to deliver Mr. Bullet ...
The 'sudo' keyword in Unix and Linux allows users to execute certain commands with special-access privileges that cannot otherwise run on a given machine by a user with a lower level of clearance.
Some Linux commands are no longer in use. These commands may still be available, but it's best to avoid them. Each of these commands has a newer replacement. Over the decades that I've been using ...
Learn the ABCs of BSD.