Children use all their senses to learn things. Through play, they learn physical aspects of thing, they learn how thing work, and how things are organized. Through play, children also learn social skills, such as sharing, cooperating, respect, etc. The websites below, will give you more in0depth information.
In taking numerous child development classes, there are two statements that speak true of children:
1. Children learn through play.
2. A child's play day is an adult's work day.
I personally don't like the word "play" as it gives the connotation that a child is manipulating objects or interacting with peers without any planning, motivation, or goals. In other words, it seems like "play" is unplanned and undirected. The truth is that children "work" very hard to "play". I personally like the word "explore" much better. Children are really "exploring" when they are playing. They are exploring what objects are and how they work. They exploring what socialization is and how to make and maintain friendships. They are exploring their emotions and feelings when they don't get to "play" what they want.
So, "why is play important in helping children to learn?" - because through "play" children can "explore" and this is how they learn about themselves, others, and the world around them.