A group of over-sampling methods for avoiding the unwanted visual effects or artifacts caused by limited display resolution. These aliasing effects include jaggies (staircasing along diagonal lines), moiré effects (checkerboards), and temporal aliasing (strobing) in animated scenes.
Maya provides various solutions for edge aliasing and for shading aliasing. Some anti-aliasing techniques reduce performance, and will increase render times. Try to find the solution that gives you the best balance between image quality and performance.