what is antialiasing?

the subject of the thread says it all.

antialiasing is a smoothening of the picture, by making the edges in the lines of your monitor image go away , search google for more info on it.

if you have a good computer turn it on, and push everything to max on settings. turn on after effects too.

Google is your friend

http://www.widearea.co.uk/designer/anti.html

In a nutshell, anti-aliasing adds subtle pixel color shading to blocky pixel based images to fool the eye into thinking it is looking at smooth graphics.

Think of a diagonal staircase. Now fill the steps with a bunch of cement to make it a smooth ramp. If the steps are pixels on your screen representing a diagonal line, then anti-aliasing acts as the "filler-cement" to make that diagonal line smooth, removing the staircase-effect.

It removes the jaggies on the screen

You will notice it zoomed in
try zooming in at 0 then turn x4 on if your card supports it