You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is According to Piaget's Cognitive theory, the sequence of development has been categorized as: and explain in detail?
According to Piaget,  the ages between 6 and 12 roughly approximate the third  major developmental stage of cognition, that is, the phase of concrete operations. Piaget proposed  the following four major periods of intellectual development:

Sensorimotor: Birth to 18 months
Preoperational: 18 months to 7 years
Concrete operational: 7 to 12 years
Formal operational: 12 years and onward.

Pediatric Dentistry Infancy Through Adolescence Fourth Edition P: 469