stages

• Sensorimotor (2 years): Infants think by interacting with the world using their eyes, ears, hands and mouth. Towards the end of this stage, they develop object permanence.
• Preoperational (3-7 years): Development of language takes place. Children at this stage cannot properly understand how ideas like number, mass and volume really work and are unable to understand other people's perspectives .
• Concrete operational (8-11 years): Children begin to be able to solve problems and reasoning becomes logical providing issues that are concrete and they can understand the theory of conservation
• Formal operational (12-18): Develops abstract thinking which enables individuals to think through complicated ideas in their heads without having to see concrete images and reasoning about hypothetical situations..
• Piaget's stages of cognitive development: Sensorimotor Stage, Preoperational Stage, Concrete Operational Stage, Formal Operational Stage.