"One lump or two?"
Camels come from Asia and have evolved to live in deserts and go long distances on little water. The humps on their backs are fat reserves for energy, keeping the rest of the body cooler.
The Dromedary or Arabian Camel has only one hump and the Bactrian Camel has two humps. Both are domesticated, but only Bactrians still exist in the wild.
The Bactrian Camel, Camelus bactrianus, is mainly domesticated, but some wild herds remain on the steppes and deserts of Central Asia.
The Dromedary, Camelus dromedarius, is entirely domesticated, mainly in Arabia and North Africa, although a feral group live in the wild in Australia.