pwd, cd, & ls
pwd – present working directory – shows the full path of the current directory you are in
pwd
cd – change directory – navigates to a different directory
cd /path/to/new/directory
cd /etc/default
ls : list the items in the current directory
ls
ls -l :list the items in the current directory with permission, ownership, and time information
ls -l
ls -a
ls -R : lists sub-directory items
ls -R