This command moves you to the "/usr" directory. "/usr" becomes your current working directory.

cd /usr/fred

Moves you to the "/usr/fred" directory.

cd /u*/f*

Moves you to the "/usr/fred" directory - if this is the only directory matching this wildcard pattern.

cd

Issuing the "cd" command without any arguments moves you to your home directory.

cd -

Using the Korn shell, this command moves you back to your previous working directory. This is very useful when you're in the middle of a project, and keep moving back-and-forth between two directories.