The human brain consists of three main parts which are cerebrum, cerebellum and medulla oblongata.
Cerebrum
Cerebrum is divided into left and right hemispheres and each hemisphere is further divided into four lobes which are frontal, parietal, occipital and temporal lobes. Cerebrum controls voluntary actions, actions which can be controlled by our own will, such as walking, reading, speaking and others.
Cerebellum
Cerebellum coordinates muscular movement and maintains body posture and balance.
Medulla oblongata
Medulla oblongata controls involuntary actions, actions which cannot be controlled by our own will, such as heartbeat, homeostasis, peristalsis and others.