cd - examples in UNIX

To navigate to a directory, if forgetcode directory if exists. (Relative navigation)
cd forgetcode

To go back one directory and then go into the home/users/next directory. (Relative navigation)
cd ../home/users/next

To go back two directories. (Relative navigation)
cd ../../

Typing just cd alone will move you into the home directory.

Absolute directory navigation, when you mention the path with / it is called absolute navigation and / denotes root directory.
cd /etc/

Difference between absolute and relative navigation

Absolute navigation is very helpful when you know the path of the directory and the command will give same behavior irrespective of present directory, Relative navigation is dependent upon current directory and is very useful the path of the parent directory is unknown