Qualitative Differences: Qualitative differences refer to significant changes in cognitive abilities or ways of thinking as children progress through specific stages. For example, going from concrete operational thinking to formal operational thinking involves a qualitative shift in abstract reasoning capabilities.
Cognitive Development: Cognitive development refers to the growth and change of mental processes such as attention, memory, language, problem-solving, and decision-making over time.
Piaget's Theory of Cognitive Development: Piaget's theory proposes that children progress through four main stages (sensorimotor, preoperational, concrete operational, formal operational), each marked by specific qualitative differences in their cognitive abilities.