What is ecology? Why does it matter?.

What is ecology? - The branch of biology that deals with the relations of organisms to one another and to their physical surroundings.

Why does ecology matter? - Ecology is the study of the relationships between living organisms, including humans, and their physical environment; it seeks to understand the vital connections between plants and animals and the world around them. Basically it's important because of the insights it provides about the ways in which people and nature depend on one another.