The document discusses principles of skill learning and motor skill classification. It defines a skill as the ability to achieve predetermined results with consistency, coordinated movement, minimum effort, and through practice. Motor skills can be classified based on precision of movement (gross vs fine), type of movement (discrete, serial, continuous), and predictability of the environment (closed vs open). Closed skills have more environmental control while open skills have less predictability. Motor skills involve both innate and learned abilities and can be combined into more complex motor programs.