The brain can be divided into three parts,
Cerebrum: the cerebrum is divided into different parts called lobes. Each lobe has it's own job to do, but all of the lobes work together to help us respond to the world around us.
Brainstem: the brainstem connects the base of the brain to the spinal cord. It looks like a stem. It controls critical functions, like your heart rate, breathing and sleep/wake cycles.
Cerebellum: the cerebellum is a small part of the brain that is responsible for mortar learning, sense of body position, balance and fine movement coordination.