cd = change directory

cp = copy

mv = move

rm = remove and erase

ls = list what is in the directory

ls -l = list what is in directory with more detail

pwd = find out where you were

mkdir = make new directory

chown = change owner

chown -R = change owner of everything in specified directory

su = switch user

chgrp = change group ownership

chgrp -R = change group ownership of everything in specified directory

diff = compare two files