Sudo

sudo is a shell command on Unix-like operating systems that enables a user to run a program with the security privileges of another user, by default the superuser. It originally stood for "superuser do", as that was all it did, and this remains its most common usage; however, the official Sudo project page lists it as "su 'do'". The current Linux manual pages define su as "substitute user", making the correct meaning of sudo "substitute user, do", because sudo can run a command as other users as well. Read more on Wikipedia