adduser
Creates a new user
usermod -aG sudo paul
Gives user profile (in this case, 'paul') admin power
exit
Closes current ssh session
sudo apt-get update
Updates the list of packages and versions listed by the apt repositories
sudo apt-get upgrade
Upgrades any packages that have a new version reported by apt-get update
wget
A download tool
crontab -e
Edits the cronjob file. Cronjobs are automated request that you setup.
rm
delete one file
rm -r
delete one directory
rm gos*
deletes all files with gos in the beginning
df -h
show disk usage