Just like a job is an adult's work, play is a child's work. It is as important as walking, talking, and sleeping. Playing allows a child to freely explore, experiment and make sense of the world around him. It is not only fun but it also helps them learn new skills, solve problems, overcome challenges, be creative, and form relationships. Unfortunately these days, the concept of free play is dying out. Children (even toddlers) spend a vast majority of their free time in structured classes and the rest of their time watching television or playing with electronic gizmos.

Play stimulates Imagination and Cognitive Development

Role-play and pretend play are very important for a child's creative and cognitive development. By dressing up as a superhero or a policeman and conjuring up scenarios, a child experiments with different identities and different situations. He not only uses his vivid imagination to come up with ideas but also uses his cognitive skills to negotiate with imaginary characters and solve problems when the 'pretend' situation requires him to. This kind of play often reflects issues that a child is trying to come to terms with (e.g. a new sibling) or is a mirror of an incident or a situation that he has been exposed to. Hence, it is very important for parents to be in tune with their children, as this will enable them to pick up clues as to what is happening with their young ones
You may have noticed that your toddler has suddenly started talking to himself or to his toys. It may seem a little crazy to you - but this is one way that a child uses to spur his imagination. This is called imaginative play and is very important for children. Since by the age of 2 - a child knows what symbols are (and how objects represent things) - he uses this ability to use / say, a block of wood as a car or a ladle as a magician's wand. By doing this he learns that one thing can be used for another.
So what can you as a parent do to make the most of your child's play time? Always follow your child's lead. Provide him with an object or a toy and see what he does with it. Even if he plays with it the wrong way, let him be. Let him show you a 'new way.' Even if your child is trying to stack blocks, show him how to do it and let him try on his own. Provide him with just enough help to keep frustration from settling in.

Play promotes Social Skills and Cognitive Development

During the pre-school years, when toddlers play side by side even without talking, they are actually learning something. They are learning to interact, negotiate, and share with one another i.e. they are learning to form healthy social relationships. A child's interpersonal negotiation strategies not only help him to become more social but they also help him with his cognitive skills.
Encourage your child to be social. Allow him to make friends and take him to visit them or ask them to visit your child.

Play helps Physical Development and Cognitive Development

Physical play as everybody knows helps physical development i.e. development of gross and fine motor skills. Pedalling a tricycle or kicking a ball not only helps a child improve coordination but also helps him build leg muscles. These are important for the development of his gross motor skills.
Fine motor skills improve through activities like stacking blocks and completing puzzles. Not only do they improve a child's finger dexterity and coordination but they also help his matching and shape recognition skills to develop.
Set a good example. Try to take your child out to the park as much as possible. Climbing monkey bars and kicking the ball around will improve his larger muscles. When indoors, play games together. Build a house made of blocks or dance. Do something interesting to keep him active and moving.

Play promotes Natural Curiosity

All children are born curious since everything around them is new. Therefore, it is imperative to stimulate this natural curiosity and imagination and one way of doing this is through play. Going to the park could become and adventure for them. They observe things around them (e.g. trees, people, swings) and see how everything fits in together. They also learn by exploring and touching things and feeling the different textures. They learn that sand feels different from grass and both of these feel different from the iron the monkey bars are made of.
Play is a simple activity but promotes imagination and development in a child.