Squamata is the the order of reptilia that has the most species within it. It contains both the snakes and the highly numerous lizards.
This order has many members, and is usually divided up into several suborders for ease of classification:
Members of the order squamata make up the majority of reptile species today. Members of this class vary greatly in size, from a few centimetres to several metres in length. There are no specific features to look for in determining a reptile is from squamata, instead the absence of features from the other orders is looked for, as is the presence of features specific to the suborders of this order.
Lizards can be distinguished from snakes very by a few simple features. Lizards have external ear opening, whereas snakes do not. Snakes have kidneys that are placed far forward in the body, but the kidneys of lizards are further back. Snakes usually have loosly connected jaws that allow them to swallow large prey, but lizards do not. In addition, most lizards have four legs. The worm lizards are generally more similar to lizards than snakes.