What is a Reptile?
A reptile is generally classified as a vertebrate animal of the class Reptilia which includes snakes, lizards, crocodiles, turtles and tortoises; these last two being in the order of Testudine. That definition is very broad and the subclass of Anapsida breaks down into orders, suborders, and etc. if you want the whole breakdown go see the Reptile Database.
“Taxonomy gives me a nosebleed so I leave it to the scale counters (Taxonomists) to sort it out and then whine when they change things.”
For our purposes on this site we are going to use common language for the most part and each of the following links will supply you with further in-depth information into specific reptiles such as bringing a new reptile home, their captive care, Reptile Shipping, Conservation, feeding & more. If you happen to be looking for something particular which may fit your apartment setting check out this piece The Ultimate Species of Reptile for Apartment Living or 10 Questions to a new pet.