What are the differences between animals belonging to the Aves group and those in the mammalia group?

Explanation

Aves includes birds which are oviparous i.e., lay eggs. The mammalian groupo include those animals which are viviparous. i.e., lay young badies. They also have mammary glands for the production of milk to nourish their young. The body of birds is covered by feathers whereas skin of nammals has hairs and seat and oil glans.