So, do you know what a camel is? It's like a big, humpy animal that lives in the desert, right? Well, a dromedary is a specific kind of camel.
Here's the thing: there are two types of camels: the dromedary and the Bactrian. The dromedary is also called an Arabian camel, because it mostly lives in the deserts of the Arabian Peninsula (that's a place where people live and it's very hot and sandy).
The dromedary is different from the Bactrian camel in a few ways. It only has one hump on its back, whereas the Bactrian has two. And the dromedary can run faster and farther than the Bactrian, so people use it more for racing and transportation in the desert.
But both types of camel are very good at living in the desert because they can go a long time without water, and they have special eyelashes and nostrils to keep sand out of their eyes and noses. Plus, they store fat in their humps so they have energy to use when food is scarce.
So there you have it: a dromedary is just one type of camel, and it's good at living in the desert. Cool, huh?