The understanding of the importance of play is nearly universal. Through play children (and adults) build so many of the skills they will use in childhood and throughout their lives. That is how we as parents learned many of the skills we gained as children. For example, when children play games with conflict, or experience real conflict during play, they learn conflict resolution. Most play includes turn taking and give and take. This promotes social and pro-social learning. All play teaches us something.
Many parents intuitively understand another crucial benefit of play: relationship building. Parents often begin playing with their children from their infancy. Simple play like rocking, singing, and making faces are often the start of a play that grows increasingly complex over the course of childhood and beyond. As the child ages and grows, the evolving play continues to help build the connection between parent and child.