The Defintion of AA (anti-aliasing) = It is refers to a method to reduce the brightness levels between two neighboring pixels by overlapping the colours in the difference level to neighboring pixels. This make the images appear smoother.
The defintion of AF (anisotropic filtering) = In 3D computer graphics, anisotropic filtering is a method of enhancing the image quality of textures on surfaces that are far away and steeply angled with respect to the camera. Like bilinear and trilinear filtering it eliminates aliasing effects, but introduces less blur in the process and thus preserves more detail. Anisotropic filtering is computationally relatively expensive and has only recently become a standard feature of consumer-level graphics cards
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