The cerebrum is the largest part of the brain and is responsible for thinking, decision-making, memory, sensory perception, and voluntary muscle movements. While it plays a role in planning and initiating movement, it does not directly regulate balance or coordination — those functions belong to the cerebellum. For example, the cerebrum might help you decide to reach for a glass of water, but the cerebellum makes sure your hand gets there smoothly and accurately without knocking it over. Confusing the cerebrum with the cerebellum is common due to their similar names, but understanding their roles is important: the cerebrum thinks, the cerebellum balances.