Children's games are defined as activities with imagination as the means, voluntariness as the core and entertainment as the purpose.
Classification from the perspective of cognitive development: (1). Sensory sports games; (1-2 years old, playing the most before two years old) (2). Symbolic games (2-7 years old, reaching the peak at 3-5 years old) (3), structural games (3-6, 7 years old); (4) Rules game (developed after four or five years old)
The common ground is to train children's learning and cognitive abilities.
But children's games also include intellectual games, sports games and music games. Now there are some online children's games on the emerging Internet, including sports games, but sports games can't directly explain children's games.