The pushd and popd commands on linux, and the "cd -" command
The pushd and popd commands use a stack to keep track of directories that you have been to. If you want to go to another directory and then return to it later, use the pushd command:
pushd ~
this goes to your home directory, and saves the directory you came from. If you later type the following:
popd
you will go back to that saved directory.
If you just want to go back to the prior directory you were in before a cd command, you can type:
cd -
and this takes you back there immediately.
