Good Afternoon,Infancy through early childhood is a time marked by rapid developmental changes that begin to demonstrate who a person will become. Children not only go through periods of amazing physical growth, but also swift mental development (Broderick & Blewitt, 2020). Cognitive abilities linked to thinking, memory, and reasoning emerge and grow throughout a child’s development, however, not all children grow and develop at the same rate (Broderick & Blewitt, 2020). Each child is unique and obtains the appropriate developmental skills to complete complex tasks at different levels and within their own pace. Several developmental theories let professionals appropriately assess children and keep track of developmental progress. For example, Jean Piaget developed a childhood development theory involving stages children experience on their way to mental maturity (Broderick & Blewitt, 2020). Piaget’s theory revolved around particular milestones, which are significant benchmark points allowing professionals to understand and measurea child’s physical, cognitive, emotional, and social developmental progression. The four distinct stages of development that Piaget surmised children move through are: sensorimotor stage (birth to 2 years), preoperational reasoning stage (2 to 6-7 years), concrete operational reasoning stage (6 -7 to 11-12 years) and the formal operational reasoning stage (11-12 years and throughout the rest of life).Piaget’s theory and work has helped modern developmental psychologist to further the field and has aided in developing new ways to understand and test cognitive development.