Help me understand relationship between refresh rate, FPS, vsync

Hello,

As I understand it, the vsync feature makes it such that your FPS will not surpass your monitor refresh rate.

What happens though if your monitor refresh rate is 140hz, you don’t hit vsync, and your FPS don’t get to 140? Do bad things happen graphically?

On the flip side, what If you don’t enable vsync and your FPS is higher than your refresh rate?

I’m only asking these questions as I’m running into issues while I try to simultaneously stream and record while I play, I’m so confuse which scenario is best…, one value being higher than the other or locking them together with vsync.