At this stage, toddlers use all their skills to become good problem solvers. They begin to understand the patterns and actions they need to perform, and in what order, to reach a goal-this is known as "motor planning." Through imitation, they come to understand the functional use of objects and use that knowledge to be effective in the world. They learn that some behaviors lead to certain reactions, for example, that putting away toys will earn them a hug from mom or dad.