Here's some info regarding baby play up to 1 years old and the link below has more details:
http://blogs.goddardsystems.com/Cedar-Park-TX/2009/09/30/...
There are a myriad of developmental skills that children learn through play. From their infant to Pre-Kindergarten stages, children are experiencing and learning new things each and every day. With play consuming most of their time, there are different things children learn during every stage of their growth.
Infant to Six Months: Everything is a baby’s first. For example, the first time a baby opens his eyes in his bassinet, he discovers something new – an animal on his mobile. The next morning, there it is again. Will it be there tomorrow? Yes, and then baby learns to trust that when he opens his eyes he will always see the mobile’s giraffe looking back at him. Babies will engage in play first by responding to sounds, then by following objects and people with their eyes. Your baby will demonstrate his memory by repeating an action that made you laugh yesterday. Once infants can hold a rattle a whole new world opens up – you will watch them turn it over, bang it, shake it and even taste it. Rolling over also widens a baby’s world from what is placed before him to 360 degrees of eye-catching curiosity. The new world is fun.
Six Months to One Year: Baby is now his own driving force to play. He no longer needs an adult or older sibling to spark his interest. Rolling over and sitting up has created choices and as he discovers how to move from lying to sitting, he is covering ground and taking aim at his own source of interest. Place toys within and outside of your baby’s reach to encourage self-discovery and motion. Your child is brilliant and will look at a familiar object when called by name. Babies not only want to turn objects around, they want to talk to them and use them the way you tell them to use them. See my hands! You say “clap” with a smile on your face and baby wants to clap and smile, too.