Solitary play is just what it sounds like—when your child plays alone. This type of play is important because it teaches a child how to keep himself entertained, eventually setting the path to being self-sufficient. Any child can play independently, but this type of play is the most common in younger children around ages 2 or 3. At that age, they are still pretty self-centered and lack good communication skills. If a child is on the shy side and doesn't know his playmates well, he may prefer this type of play.
During the first 2 years of life, children essentially play in 2 important ways. They play with adults and they play with objects. These 2 types of play prepare children for solitary play, the play they engage in after they are 2.