Are Nikon F, AI, AIS, and G mounts the same?

I'm buying an adapter to fit nikon lenses for my camera, and there are different adapters on ebay, saying Nikon F adapter, Nikon G adapter, Nikon AI adapter, and so on. They're all different prices too, so I was wondering if the mounts are different? Will buying just one of them do for all of my old (manual focus) and new Nikon lenses?

Basically, they are all F-mounts with different levels of technology.

http://www.kenrockwell.com/...y-lens.htm
http://imaging.nikon.com/...ossary.htm

If any of the Nikon lenses you want to adapt is a G lens, you should select an adapter that can work with it. These lenses lack a mechanical aperture ring, and aperture is normally controlled electronically by Nikon DSLR's and some Nikon film SLR's. Adapting to a different brand body you lose that electronic interface, but Nikon G adapters have their own mechanical control of the aperture control lever.