The primary function of the human brain is to serve as the control center for the entire body, managing bodily functions and processing sensory information. It is responsible for a wide range of activities, including thinking, remembering, problem-solving, and coordinating movements. Additionally, the brain regulates vital functions such as heart rate, breathing, and homeostasis. By communicating with the nervous system, the brain allows for responses to external stimuli and plays a critical role in emotional and cognitive processes, thus shaping behavior and interactions.