If you do command line work under Linux, you probably are aware that when pressing <TAB> automatically completes your
command, or give you options for it that are currently available. For instance, when entering cd l en pressing <TAB>,
bash gives you a list of all directories starting with an l, which you can select instead of type. If there is only
one available directory that starts with an l, it will automatically fill this in for you.
A great way to speed up your CLI development work, and an even better way to get acquainted with all options that are available to you for certain applications.