As a new born we encountered with lots of sensation and begin making sense of them with greater speed. The association areas of the cortex- those linked with thinking memory and language are the last brain areas to develop, as they develop the child mental ability grows, hence our physical and cognitive development go together. Cognition refers to the mental activities associated with thinking, knowing and remembering. Different development psychology gave different theories of the child cognitive development. Though the work of Piaget is very pioneer and funded the phenomenon of cognitive development of the child.