This is a plugin for oh-my-zsh.
It keeps track of the last directory you cd to.
When starting a new terminal, it automatically cds to that directory again.
If zoxide is loaded, then the plugin uses __zoxide_z instead of cd.
This is very useful if you want to quickly start two terminals, one for a source directory and one for a build directory.
You start in one terminal and cd to the source. Then you open a new terminal, which starts in the same directory an you cd to the build directory.