What is "Anti-aliasing"?

[Burke22]

Mario Kart Wii is a little slow, (it was perfectly fine yesterday) and it says that it's "playable" and that i could turn anti-aliasing off to avoid overbloom, what is that and how would I turn it off?

[Burke22]

nevermind i fixed it

[AnyOldName3]

In case you're still interested in knowing what AA is, it's basically the name for methods of removing aliasing (which is obvious from the name, but not especially helpful). Aliasing is when you have some data, but because of some issue with how you're measuring or presenting it, it ends up looking wrong, so in the context of computer graphics, it's stuff like the edges of shapes looking pixelated and jagged because you've only got a limited number of pixels with which to display the shapes.

The two main classes of AA in use are super-sampling AA (e.g. SSAA, MSAA) which more-or-less renders the scene at a higher resolution than your monitor and downsamples the result so you get multiple samples per pixel, and post-process AA (e.g. FXAA, MLAA, SMAA), which looks at the image after it's already rendered and makes a best guess about what it's supposed to look like, with varying degrees of success depending on the technique.