rasterizing

What is rasterizing, and what does it do?

Also..

What is "anti-aliased" and what's it's purpose?

hard to explain
RASTERIZE: It's liking making the layer into one. Or making it so it cant be edited as something else. I prob confused you.

ANTI-ALIASING: Is like i think making the edges around something look smooth by using coulours in between the ones u used instead of just having it one colour on the background.

Rasterizing turns something into a pixelized or bitmapped form, which means that it can no longer be resized or enlarged. The opposite would be a vector image, which is all based on mathematical equations and coordinates, making it very easy to enlarge to any size needed, or reshape it completely. An example would be the text in PS6. When you first type it in, you can resize it, and even use the pen tool to reshape it if you want. But after you rasterize it, you can no longer reshape it or enlarge it without making it look 'pixelated'.

Anti-Aliasing is basically what ps6user said. It pretty much just blurs the edges of something to make it appear smooth. For example, a circle. It is technically impossible to make a circle on a computer screen, because it is just a grid of very very small squares. But with anti-aliasing on, it will blur the edges, which tricks your eye into seeing a smooth curve.