Biology is the study of all living things, from microscopic organisms up to the largest lifeforms we know about. It's important to know how living things work, because humans are living things. Knowing about biology helps you to understand how your own body works. It's also important to be able to understand how different living things use different ways to do the same things, like making energy, eating, and moving. These things help us to find new ways to solve problems. Biology is also important because many living things are harmful, and learning about them can help us learn how to overcome disease and infection. Basically about life and what we need for life.