Center play , free play, and group play all play an important role of a child's learning. Why some people may call it play I call it learning areas.
Center play is more focused on that particular area. The child learns about things that goes on in that area. Those areas offers many different things to learn.
Free play the child has freedom to go to any area with in the classroom. The child may come and go as he/she pleases. Thou the child my wonder from areas to areas he is still learning. He is exploring the different areas to see which one that may excite him more. Group play is more structure that is when we come together as group to learn something new and to express our thoughts and to listen to the thoughts of others.