one can render multiple samples around a fragment being rendered. The number of samples is configurable, as
well as their locations.
anti-aliasing (MSAA) generates several fragments with slightly different
sub-pixel locations, and averages the result.
runs the fragment program just once
locations are pseudo-randomly positioned throughout the pixel region.Source: AnandTech
No multi-sampling vs. 8x MSAA (Zoomed 200%)