Affordances can be described as the possibility for action by an object substance, or situation. Infants learn the affordances of the physical world around them as they are perceptually learning. Infants discover that flat surfaces can be crawled on and small objects can be picked up and examined. They learn about the consistency of liquids and that they can be spilled and that they can fit into some spaces and not others. Learning the affordances of objects and situations allows infants to build their knowledge and interact with the world around them.