Types of material maps?

I feel like this would be a great subject for a MapCore article. I'm wondering about the various material maps people use for world or model textures. Stuff like the albedo maps, roughness, specularity, detail maps etc. Some discussion on their uses and methods of creation would be great too. I know a number of these are used in CS:GO and other modern engines, just not sure of what situations are best to use them in, or how to create them really.

Quote from esspho

When I started to make props and textures this article gave me a pretty good overview of what to do and how to do it regarding individual texture maps .

There is also a good summary over at the polycount wiki.

Hopefully that helps for starters but I'm just a hobbyist in that regard. Maybe some of the pros can pitch in?

Thanks for the links! Some good resources. I'm hoping will2k or FMPONE or someone with some Source texture creation experience will chime in at some point.