Oculus Link is a feature on the Quest/2 that allows you to play content from your gaming PC on your Quest/2 headset. With Link your potential library of games expands dramatically, including titles you can buy on Steam or for Oculus Rift. Check here for compatibility requirements.
The Oculus store sells a Link Cable for $79, but you can use any high-quality third party cable as well. Oculus even recommends this one from Anker.