Depends on your shell, if you execute `which -a cd` it will show you /usr/bin/cd in addition to the built-in command.

(zsh has which as a built in command, apparently bash doesn't, which causes the different output). It's unclear to me what /usr/bin/cd actually accomplishes though, even in bash.

(final edit I hope, I found an explanation of sorts for /usr/bin/cd: https://unix.stackexchange.com/a/50060)