What exatly is antialiasing?

[ale555666]

I know this make games look better. But how?
What is it?

 

[cjl]

It reduces pixellation and can help smooth out hard edges. Here are some examples:

http://www.meko.co.uk/glossaryimages/antialiasing.gif

http://www.gemaga.com/wp-content/uploads/2007/12/anti-aliasing.thumbnail.png

http://www.snowbound.com/images/antialias.gif

 

[xc0mmiex]

^ what he said