In some rare cases, at least for me, we may need to change to our user home directory, via
cd ~, and then go back to what we were doing in a project folder. The problem is that going back to our project folder probably means
cd'ing our way into it.
Thankfully, many *nix systems come with the built-in (AFAIK)
popd commands, which build and keep a directory stack. While
pushd adds the directory path to the top of the directory stack,
popd removes it from the stack.
You can get more information about these commands by typing
help pushd and
help popd in your terminal prompt. I will leave you with an example so you can get a better idea of how and when these two commands can be useful.
I hope you get the idea. You can dig deeper into these commands via
help popd, or even
help dirs. They are useful in other cases.