If you’ve been using Linux for any length of time, at some point in some tutorial or troubleshooting guide you’ve more than likely encountered Linux’s magic word: “sudo”. A casual observer probably can tell you that it’s used to access restricted functions on your computer, but there’s much more to it than that. My hope is that by taking a moment to dig into the history and inner workings of this command, you will be better equipped to utilize — and respect — the power of “sudo”. For starters, it helps to look at Linux’s ancestor, Unix.
From: Linux Insider