Play is how children learn naturally and it is as important to children's development as eating and sleeping. We all enjoy leisure activities, hobbies and play. We use our weekends and vacations to participate in sports, engage in arts and crafts, visit places of interest, play online games...whatever we think of as "fun." If it is not 'work,' it may be considered 'play." It is not solely the domain of children.
Children learn a variety of social skills through play. Play stimulates brain growth in children at the most critical time in their development. Play lays down the foundationi for later learning. Parents should not be concerned at all. When children are playing they not only learn fundamental concepts that are the basis for later academic learning, but they're also learning social skills. Building blocks is a math experience as much as it helps them develop concepts of shape, size, length and location. And with art, when they're mixing colors, they're learning hand-eye coordination and exercising their imagination and creativity. Even if a child is outside bouncing a ball, children are learning. They're learning to count, learning about shapes and colors.
Children learn to share ideas and experiences. They learn to follow rules or to invent their own. They test their physical abilities and make scientific discoveries. They test whether branches will carry their weight, learn at what point a tower will over-balance, how to solve a puzzle and show patience. Children are also able to play different roles. A child who just visited a doctor will give a doll "shots." Sometimes they can be the dog, or the "Mom." They can go shopping, drive a car, or order take-out-in fact, they can do anyting they have seen an adult do and practice with language and trying an assortment of roles. It is all about expanding the imagination.