Hi (I was in the middle of writing this up when @Alm
posted, but I've expanded on what they said a bit so I'll post it anyway.)
Antialiasing basically smooths out jaggies, or the rough edges of polygons that look unnatural in game. Like in this link
. It takes graphics power, the amount depending on the method used. So disabling it improves frame rate at the cost of some visual quality, sometimes by quite a lot.
Enabling Vsync stops tearing
from being displayed on your screen as long as the frame rate is over 60 (or 30 if you lock it to half refresh rate in settings)
Disabling vsync allows for better response times, which is helpful if you're playing competitive shooters or fast paced games. But then you will have to put up with tearing.
VRR (Gsync/Freesync) is related but different to Vsync and requires your monitor to support either standard.
Neither setting being disabled or enabled will damage anything at all.