When you watch a baby bat at a mobile, or a toddler line up blocks by themselves, or a group of children build an elaborate shop together you are watching something that looks simple but is actually extraordinary. Play is how children learn. Not a warm-up for learning. Not a break from it. Play is the thing itself. And the way children play changes meaningfully as they grow becoming richer, more social, and more complex with every stage of development. Here is a look at what