As I said in the episode, I use these less than I used to, though I do still use them.

cd , cd- and cd only let you move between a given directory, the previous one and $HOME, whereas pushd and popd let you manipulate a much larger collection of directories.

If I'm connecting to a remote VPS or something I might do this:

pushd -n ~/Community_News/; pushd -n ~/Database/; pushd -n ~/IA/; pushd -n ~/content_cleaning/
dirs -v
 0  ~                                                                                                                                                                                                                                     
 1  ~/content_cleaning/                                                                                                                                                                                                                   
 2  ~/IA/                                                                                                                                                                                                                                 
 3  ~/Database/                                                                                                                                                                                                                           
 4  ~/Community_News/

(note the '~/' at the start to make these absolute paths)

Then I might hop around between directories with for example:

pushd +4

Even this has been largely superseded by screen and tmux, I will admit.

I'm probably just old-fashioned :-)