Privileges

Privilege rings: from the most privileged to the least. Ring 0 is the innermost circle inside the diagram, and represents the most sensitive permissions; these permissions are granted to the Operating System's kernel. Since it is the innermost circle, it is the smallest one, meaning that such permissions aren't given to most users. Above this ring are several more, outer rings, listed as Ring 1, Ring 2, etc., each representing less and less sensitive privileges given to users. Ring 1 and 2 permissions are granted to programs running on behalf of the operating system (a.k.a., 'operating system services'). The outermost ring stands for the most common rights given to a computer user and user applications.

Taken from https://www.researchgate.net/figure/The-x86-privilege-level-architecture_fig1_235953591.

These notes by Miriam Briskman are licensed under CC BY-NC 4.0 and based on sources.