People  love or hate reptiles because of their polarizing effect. There are so  many kinds of reptiles all over the world. Here you will find  information about some of the more interesting species that share the  earth with us. People are afraid of  reptiles because they do not  understand their interesting behaviors and characteristics.
How To Understand the Different Kinds of Reptiles
First step you should understand the system for their organization and classification. Have in that the reptile classification system is changing, it is not constant – scientists discover new species, they often merge species from into other genera. This leads to plenty of confusion because there are so many revisions in the classification.
Reptile Classification System Of Reptiles
Reptiles are classified into four main groups known as orders:
Crocodilia  order of reptiles includes about 23 species of crocodiles,  caimans,alligators and gharials with  25 individual species of reptile;Squamata  order of reptiles includes more than 7,000 individual species of  lizards and snakes;
Testudines   reptile order includes about  300 species of tortoises and turtles;
• Sphenodontia is the smallest order of reptilesand includes only two species of tuataras from New Zealand. They are the last living members of “Dinosaur Era.” But if you only know the orders, it is not the reason to like the reptiles. Also you should learn some interesting facts about reptiles to provoke your appreciation and curiosity.
 Interesting Facts About   Reptiles              
How Many Venomous Snakes? 
The  majority of snakes in the world are   not poisonous. It  is nearly two-thirds of all the 2,700 species of   existing snakes.So  only about 500 are poisonous, of them just 30 – 40 of   are   harmful to  humans. All in all less than 2 percent of all snakes.
 Not True for Australia 
Australia is the only continent where poisonous  snakes are  more than non-venomous snakes. One of the world’s most poisonous snakes –  the taipan lives there.
 The Long Life of Tortoises 
The giant tortoises live longer than any other animal on the planet  They can live nearly 180 years.
 A Cold-Water Turtle? 
Emydoidea blandingii or so called  Blanding’s turtle swims  under the ice in the Great Lakes region of the United States.
 Snakes and Lizards Tasting the Air 
Snakes and lizards have a special organ, called  Jacobson’s  which helps them “taste” the air around them. When a lizard or snake  flick  its tongue out, actually it  collects particles from the air.  Then it passes the particles over the Jacobson’s organ in order to  decipher the air.
source: http://petscomfortadvisor.com/kinds_of_reptiles_understanding_the_world_of_reptiles.html