In this video I'll tell you about the root user.
The root user is a user that always exists.
It lives in the Linux kernel. We call that kernel space.
And because it lives in the Linux kernel, the root user needs no permissions to do whatever the root user wants to do.
Root has kernel level access, and permissions.
Are not dealt with at the kernel level.
That makes root an unlimited user account, and using this account should be avoided at all times.
On modern distributions, the root user often. Doesn'T even have a password, which effectively disables the user.
But you could set a password if you want.
But don't forget, you should never login as root.
Instead use either su, which is a poor choice in fact,
or sudo. Sudo is much, much better. To get root permissions.
Let me make a drawing so that I can show you a bit about. Kernel space and user space and the. Way how the Linux operating system is organized.
In the design of the Linux operating system there are two
essential parts and we can draw a line in the middle.
The lower part is kernel space, kernel. Space, which is also referred to as system space.
This is where the kernel is used. The heart of the Linux operating system
and the mission of the kernel is to address the hardware in your system.
The kernel is doing so by using drivers.
And in this kernel space there is. Also a user account, and we call that user Root.
Root is a default user that exists. On all Linux distributions.
It's a kernel space user, and as such there are no limitations for the. Root user, which makes it very dangerous.
Then we have user space, and in user space you are going to
run your applications and your users are going. To do their work.
Now, the user space from user space, sometimes you need access to what the kernel is doing, and that needs to happen in a secure way.
And that is why on the boundary between user space and kernel space,
systems like permissions are used and interfaces like system calls are provided.
Now, the interesting thing here is that permissions are mainly for allowing user space to access parts of kernel
space, like users who want to access a file. But if you are the root user, you are beyond
permissions, and that is why we will see that if you are root, even if you don't have permissions
at all, you can read the files anyway, and that makes this root user so very dangerous.