Assimilation is a process in which an organism incorporates external factors into its original schema when it feels a stimulus, and modifies or reconstructs the original schema to adapt to a specific stimulus when it encounters a stimulus that cannot be assimilated by the original schema.

In essence, assimilation mainly refers to the role of individuals in the environment; Adaptation mainly refers to the influence of environment on individuals.

All cognition is inseparable from assimilation and adaptation to cognitive schema. Cognition is the product of two processes of unity of opposites: the adaptation of cognitive schema to foreign things and the assimilation of cognitive schema by foreign things.