Change Directory - change the current working directory to a specific Folder.
The syntax is cd followed by the name of the directory you want to go to.
cd /home/user/public_html to change the current working directory to /home/user/public_html.
The '/' indicates the path relative to the root directory, and no matter what directory you are in when you execute this command, the directory will be changed to /home/user/public_html.
cd public_html/ to change the current working directory to public_html/, relative to the current location which is /home/user. The full path of the new working directory is /home/user/public_html.
cd .. Move to the parent directory of the current directory. This command
will make the current working directory "/home.
cd ~ Move to the user's home directory which is "/home/username".
The '~' indicates the users home directory.