The Bactrian camel is found in Asia/Mongolia/Hundu Kush. It has two humps and much longer hair than the dromedary camel which is found in the mid-east. If you've ever seen a camel hair coat it's from the hair found on a bactrian camel. So there you go.

The easiest way to remember the difference is that a "D" has one hump and a "B" has two.