How do you go down one level in Terminal?

Changing to another directory (cd command)

1. To change to your home directory, type the following: cd.
2. To change to the /usr/include directory, type the following: cd /usr/include.
3. To go down one level of the directory tree to the sys directory, type the following: cd sys.

How do I go back one directory in terminal?

You can try it out yourself by opening a Terminal window, navigating somewhere within the file system, then immediately switching directories to another location. Now just type cd – to switch back to the prior location, and cd – again to switch back to the original location.