Antialiasing is a technique that is used to increase quality of hi-res images showed in low-res. Basicaly its to make images/textures look better.

Example:
http://en.wikipedia.org/wiki/File:Anti-aliased-diamonds.png
On left there is image without antialiasing, you see pixels on figure edges. On the right there is image with antialiasing, its smoother and looks better.

Turning it on should make models look better but will require more resources from CPU/GPU

Vertical Sync in old CRT monitors was used to achieve stabilization of image. In newest monitors it is used to control screen refresh rate and synchronize it with graphic card refresh rate

Turning it on should make animations run smoother, but it depens of how good are your both CPU and GPU

Render effects, its propably an option to turn on additional graphical effects