They are invertebrates  (without backbone).

More than 1 million species are there.  

They are small winged animals. Some insects are wingless.  

Insects live everywhere including hottest places and coldest polar zones.

They have sensory organs in their body such as compound eyes , and three simple eyes, and two antennae.

They fly to various flowers to collect the food and so help pollination

Insects have exoskeleton

The wings help the stability in their flight, and help for the protection.

There are 29 orders