Biodiversity simply means all the different types of life forms in the world. Including micro-organisms, plants animals, humans, aquatic life, and everything.
Biodiversity is important in many ways:
The large number of microorganisms and worms are responsible for formation of soil and its maintenance.
Large diversity in plants means large variety of food crops on which almost all the animals depend directly or indirectly for food.
The organic waste is decomposed by the microbes, worms, insects, etc. which is important to balance.
The aquatic life, all aquatic plants and animals are responsible for keeping the water clean without which eutrophication might occur.
The bees, butterflies, moths, birds help in pollination and seed dispersal.
Many plants and trees or their products are medically important and help in curing diseases in animals as well as humans.
All living forms are interdependent one or the other way and Biodiversity is the key in maintaining food-chain, ecosystem and sustainability among the life forms.