When you're working in the command-line interface, you may be going deep inside the directories and moving back and forth those directories can be a nuisance. There are built-in directory commands in ksh/bash that you can use to ease your change directory (cd) pain.
How do you use Bash Auto Completion?
A: The file and directory name completion are available by default in bash. To use the default auto completion feature of bash, you'll hit [TAB] Key once or twice.