what is the difference between alligator and crocodile?

Different species. Crocodiles are "Old World" and Aligators are "New World" which is to say the Americas.

They are similar creatures but belong to different animal families. The basic difference is the shape of their nose.. AAlligators have a more U shaped nose where as the crocs have a sharp or pointed nose.

You can't see an alligator's teeth when it's mouth is closed; its lower teeth fit snugly into pits in the upper jaw. In contrast, a crocodile's lower teeth are always visible. Alligators have a broad snout, while crocodiles have a thinner snout. Alligators tend to be grayish black in color, whereas crocodiles have a light tan appearance. Alligators can only be found in the southeastern United States and in some parts of China. Crocodiles can be found all over the world. In the wild, alligators tend to run away. While not exactly wallflowers, they certainly prefer their own company. Some species of crocodiles, on the other hand, have legendary tempers. The Salt Water Crocodile and the Nile Crocodile have been known to eat people. Obviously, these two creatures have more in common than not. Alligators, caimans, crocodiles, and gharials are all referred to as crocodilians, and the last 25 years have been very kind to them. Thanks to conservation efforts and threatened animal legislation, 16 of the 23 species have been returned to sustainable population levels.

I am not sure but I think the alligator has a broader nose than the croc and I also think it has to do with where they come from.

i guess they are of the same family, me too i just dont know their difference..maybe they differ in their class..Just like us we are the same humans, but we differ in our personality, and families, thats why you have your diffrent name and personality but we are the same humans..That's why we are different just like the crocodile and the alligator..

I am not so sure but from the Discovery Channel, it is said that they live at different parts of the world and they differ in size and the mouth part, whatever you call that, is also different. :p

I am not basing my answers on any search engines, my answer is based upon on what I have learned from watching National Geographic Channel. Crocodile's snouts(tip of their nose -I wouldn't even call it as nose) are more wider than those of alligator's, and they are bith called crocodilians. Croc's prefer to take care of their young on the time it hatches, while alligators only lays their eggs and leave their babies to venture in the wild. Also their size and color are much different from one another, Croc's have light brown color while alligators are more blackish.