Toads and frogs

http://allaboutfrogs.org/weird/general/frogtoad.html

"Generally speaking, though, when we think of frogs, we generally picture what are called "True Frogs"....members of the family Ranidae, containing more than 400 species.

The term toads tends to refer to "True Toads"....members of the family Bufonidae, containing more than 300 species.

The physical distinctions, however, can easily get blurred because sometimes the features appear mixed or less obvious, and certain species even legitimately fall into both categories. It is not uncommon, for example, to find a warty skinned frog that isn't a toad, or even a slimy toad! Even the more invisible stuff like cartilage structure has been found to sometimes fit both categories!"