grep
find things inside files
ls
list directory
apropos
find what manual page is appropriate
popd
pop directory
pwd
print working directory
export
export/set a new environment variable
less
page through a file
pushd
push directory
env
Look at your enviroment
cp
copy a file or directory
suo
Danger! Become super user root DANGER
man
read a manual page
exit
exit the shell
echo
print some arguments
mv
move a file or directory
hostname
my computers network name
find
find files
mkdir
make directory
cat
print the whole file
xargs
execute arguments
rmdir
remove directory