The cerebellum
Involved in the coordination of movement

Compares what you thought you were going to do (according to motor cortex) with what is actually happening down in the limbs (according to proprioceptive feedback), and corrects the movement if there is a problem.

The cerebellum is also partly responsible for motor learning, such as riding a bicycle.

Unlike the cerebrum, which works entirely on a contralateral basis, the cerebellum works ipsilaterally.

now the cerebellum is regarded as a structure that can help not only motor but also nonmotor regions to do their work effectively. In fact, the cerebellum has been compared to a powerful computer, capable of making contributions both to the motor dexterity and to the mental dexterity of humans

immature at birth but develops through childhood and adolescence, reaching its full structural growth by the 15th to 20th year of life

1) contains more neurons than all the rest of the brain combined.
2) a more rapidly acting mechanism than any other part of the brain
3) it receives an enormous amount of information from the highest level of the human brain (40 million fibers).