The cerebellum (Latin for "little brain") controls balance, posture, and movement. It is located below the back of the cerebrum (by the occipital lobe). Like the cerebrum, the cerebellum is divided into two hemispheres which are connected by a bundle of white fibers called vermis.
The cortex of the cerebellum consists of fine folds (folia) and gray matter, while the inside consists of white matter and groups of nerve cells called nuclei. Three fiber bundles, peduncles, connect the cerebellum to the midbrain, the pons, and the medulla oblongata, all of which are part of the brain stem.
The cerebellum uses commands from the motor cortex in the cerebrum in order to coordinate voluntary movements. The cerebellum also sustains balance and posture by controlling muscle tone and limb position.