Vertebrates and invertebrates

Animal world consists of millions of different animals with a wide diversity.

We may have grouped animals based on different criteria. Mode of locomotion, body shape, body colour, size of the body and mode of nutrition are some of the criteria you can use to group animals. Therefore you will learn that there is a vast diversification in animals. Human is also a member of this diversified animal world. 

 Animals are grouped for ease of identification and study, considering criteria such as mode of locomotion. For example bats, butterflies, crows are grouped as 'flying' animals. However, sciencetific classification becomes essential due to the vast diversity in other features. Many animals, including humans, have a backbone observed as the central line of bones. Also some animals do not possess a backbone.   

 Animals can be divided into two groups as animals with a backbone and animals without a backbone. Animals with a backbone are called vertebrates;

                                                     Ex: human, birds, fishes, reptiles

  Animals without a backbone are called invertebrates.

                                                   Ex: insects, mollusks, arachnids, annelids

Here you can get more details about above categorizes.