To understand this important concept better, let's take the popular x86 architecture as a real example. Right from the i386 onward, the Intel processor supports four privilege levels or rings: Ring 0, Ring 1, Ring 2, and Ring 3. On the Intel CPU's, this is how the levels work:
Figure 1: CPU ring levels and privilege
Let's visualize this Figure 1 in the form of a Table 2: x86 privilege or ring levels:
| Privilege or ring level | Privilege | Purpose |
| Ring 0 | Highest | OS code runs here |
| Ring 1 | < ring 0 | <Unused> |
| Ring 2 | < ring 1 | <Unused> |
| Ring 3 | Lowest | Application code runs here (userland) |
Table 2: x86 privilege ...
