Linux command line for you and me
Something to note which wasn't mentioned here is that `cd` is not a binary executable, but instead a shell command. You won't find it anywhere in /bin, /sbin and so on. That's also why `sudo cd ` doesn't work, `sudo` will try to execute `cd` as root but it's not an executable so it won't find it. (tip: do `sudo -i` instead)