What is Frog?

There are around 3,900 species of tailless amphibians, or Anura, also called Salientia, including the frog and toad.

Amphibians

Frogs are members of the zoological class called Amphibia.

Amphibians are cold-blooded (or poikilothermic) vertebrate animals. They differ from reptiles in that they lack scales and generally return to water to breed. 

They are one of three types of Amphibians. Anura, also called Salientia, (frogs and toads), caudate (salamanders and newts) and caecilians (worm-like amphibians).

Herps and Herpetology

Amphibians together with reptiles make up a larger group called Herps. The study of reptiles and amphibians is called Herpetology. Herp comes from the Greek word herpeton, which basically means "creepy crawly things that move about on their bellies."

A herptile is an individual herp. A person who keeps and breeds herps is called a herpetoculturist and the hobby is called herpetoculture.

*They have a ridge of very small cone teeth around the upper edge of the jaw. These are called Maxillary Teeth.

Frogs often also have what are called Vomerine Teeth on the roof of their mouth. 

They don't have anything that could be called teeth on their lower jaw, so they usually swallow their food whole. The so-called "teeth" are mainly used to hold the prey and keep it in place till they can get a good grip on it and squash their eyeballs down to swallow their meal.

Toads, however, do NOT have any teeth.

(source:googe/http://allaboutfrogs.org)