Cell physiology is the biological study of the activities that take place in a cell to keep it alive. The term physiology refers to normal functions in a living organism.Cognitive development means how children think, explore and figure things out. It is the development of knowledge, skills, problem solving and dispositions, which help children to think about and understand the world around them. Brain development is part of cognitive development.Cognitive skill development in children involves the progressive building of learning skills, such as attention, memory and thinking. These crucial skills enable children to process sensory information and eventually learn to evaluate, analyze, remember, make comparisons and understand cause and effectIn his theory of Cognitive development, Jean Piaget proposed that humans progress through four developmental stages: the sensorimotor, preoperational, concrete operational, and formal operational period.