ubun2

If you are asking about using the terminal, the cammand to Change Directory is cd. This only works within directories, however. By which I mean if you are in /home/user/ and you want to move to Documents you would issue the command cd Documents. Now, say you are in Documents and you wish to move over to Videos, the command would be cd ../Videos. Note that the system is case sensetive (i.e. Videos and videos are two different directories). You should really check out Ubuntu's documentation for a better understanding of how to use the terminal.