As far as appearances, they look extremely similar.
AFTs need a bit more humidity, but aside from that they are kept similarly.
They are completely different species, though, and cannot even hybridize. They are apart of the same subfamily of Eublepharinae (geckos with eyelids).
Leopard geckos (Eublepharis macularius) are from the middle east, India, and central Asia.
African fat tails (Hemitheconyx caudicinctus) are found in Western Africa.