you made it complicated again dude. AIMehdi says it's to go up and down the filesystem and you're saying it's to change the directory. earlier today i used it to change directory so that's what I know it to be used for. my example would be lets say I'm currectly in /home/user/MyDocs and I want to get to let's say .videos then I type cd /home/user/MyDocs/.videos ok I did some reading and i get it clearer now thanks