What is Root?

Hey guys, this is Matt Kids One. Today is going to be a brief little explanation of root. Now, you may or may not know what root is on your computer. If you don't know, uh, you might have enabled root before, uh, to get past maybe parental controls or get administrative access to your computer. Or you might have gone into single user mode at one point or another.

Well, let me tell you something: you use root all the time. Maybe you don't know it, but your computer always has root logged in on some console somewhere. Now, just because you don't see graphically root logged in, doesn't mean it's not logged in in the background of your computer.

Now let me explain what root is. Root is a user on your computer that, um, is the root of all users. He is like—root is universal throughout all the Unix/Linux machines. Mostly all of them would have root; Windows does not have root currently. Um, but uh, root, um, is kind of like the Windows equivalent of the system user. When you boot up your computer and the login window gets started, everything gets started; they're running as root. The user that owns them is called root (r-o-o-t).

Now, um, I might put a link in the description of the video to how to enable root on a Mac. Um, you might also notice that, um, when you boot up and you hold command S, that you're logged in as root. That's because while you're booting, you're logged in as root anyway. So why not unlog you out? Why not keep you logged in as root while you go into this single user mode which is when you hold command S while turning on your computer?

Um, so root is, um, the super user on your computer. He has permissions to edit any files, change the permissions of any files. He's the only one who can change the ownership of any file without invoking a sudo command. Sudo has something called a sticky bit which means it can run as root, um, but it's smart and it knows that you need to enter a password.

Um, if you have a Unix console, it runs as root. So all these great little things run as root, and you can just, um, I'll show you where root's home directory is, and I'm going to do this through terminal.

Um, if you type cd / space var, now I'll just do sudo -s to log in as root. Now I'll type ls /var, then I type cd root. If you haven't watched other terminal lessons, you should watch those before, um, watching this part in terminal. But basically, right now I'm in root's home directory (/private/var/root), and here's root's home directory.

You can log root in at the but, um, I prefer to just have him running my background processes and me as an administrator using the GUI. Um, you cannot delete root completely; you can delete him from the passwords file all you want, but the best you can do is wreck your computer because root is always there.

And if you go into Activity Monitor, um, you can see that there's always a process that's root. I'll just open it up right here; I just select user. There are actually a few users. Root is running all these processes; he's running the login window, he's running login. I don't know which console that's from, but whatever. And he's running all the services type of things.

You know, root is a very important thing to the Unix system and although he is also a user (or I'm not calling him a he, it's not really a person), root is, um, the root where all users bow down to root because root is always there.

Um, the root account can be quote-unquote disabled, but that's only his login that's disabled. But when the computer boots, even if his password is bang and then a hash, it'll still boot fine even if he's disabled. Um, and in fact, you can disable the root login, but you cannot disable the root user because it's always there. Otherwise, you wouldn't have any login window; who would it log in as?

I mean, there are like 12 other users on your computer, at least, that are for services and stuff. Um, so that's root—a simple explanation of root on the Mac.

So thank you for watching Mac Kids and A1. Uh, please subscribe to our videos because without your subscription, we can make all these great videos come live. And, uh, goodbye.