The Oculus Quest 2 can be used with the PC Link (requires additional cable, good less expensive ones to get on Amazon vs. Oculus) to run PC games/anything VR that runs on a PC.
When not used with the PC Link, it will run Android VR apps only.
The Oculus uses it's complete/own hardware only, when run as standalone headset (android). When connected to a PC, it acts only as a receiver, similar to the Rift and the PC's hardware is used instead. Still though, it will render with a higher resolution than the Rift, rendering still doesn't occur on the Oculus Quest 2 but on the PC. Anything else would not work anyway, as the Quest 2 doesn't have the power that is required by PC VR games. This is noticeable, when running games like Star Trek: Bridge Crew directly on it (if available), the quality on some games is miserably lowered compared to their PC version.
tldr; So, using Oculus Quest 2 with your PC has the same PC requirements as any Oculus HMD for the PC, like the Rift or Rift S.
I'm using the Quest 2 as replacement for my older Rift and it's truely an amazing solution, to be able to use it standalone as also connected. Covers all cases and it's flexible to take it to other places in the house or outside, which I couldn't do with the Rift.