Sorry in advance as I know this will have probably been asked before, however I've searched and couldn't find a definitive answer.
The Oculus FAQ says this:
Oculus Rift S and Oculus Quest don't support the same Oculus Store.
Oculus Rift S works with the existing Oculus Rift store. Oculus Quest has its own store that will have 50+ titles at launch, some of which are new for Quest and some of which are Rift titles that have been ported over.
I currently own a Rift S and am looking at getting a Quest 2. Does this mean I would potentially need to purchase a Link Cable in order to play some of the games that I already own on Rift S? Is there a list of titles which have been ported over?
Yes you will need to buy a USB 3.0 cable to use Oculus Link. I’m sure third party cables will still work with Quest 2 and Link, just as they did with Quest 1.
You can play all your Rift games when tethered with a Link cable, and you can install onto your Quest any games which support cross-buy. Here is a list of cross-buy titles; if you own the Rift version of any of them, you can claim the Quest version for free.
