Aliasing refers to an effect that causes different continuous signals to become indistinguishable (or aliases of one another) when sampled in statistics, signal processing, computer graphics and related disciplines. Aliasing also refers to the distortion or artifact that results when a signal is sampled and reconstructed as an alias of the original signal.
When we view a digital photograph, the reconstruction (interpolation) is performed by a display or printer device, and by our eyes and our brain. If the reconstructed image differs from the original image, we are seeing an alias. An example of spatial aliasing is the Moiré pattern one can observe in a poorly pixelized image of a brick wall. Techniques that avoid such poor pixelizations are called anti-aliasing.
That's what I just got from Wikipedia....if you go there they have a picture example of what aliasing can do that illustrates it quite nicely.
and lol Starcraft.
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