Recognition, identification, assimilation, apperception are comparable when they designate a form of cognition which relates a perception of something new to knowledge already acquired.
Recognition implies that the thing now perceived (as by seeing, hearing, or smelling) has been previously perceived, if not in itself then in another instance of the same kind, and that the mind is aware that the two things are identical or of the same kind.
Identification implies not only recognition, but such previous knowledge as permits one to recognize the thing as an individual member of a class of things.
Assimilation implies that the mind responds to new facts, new ideas, or new experiences by interpreting them in the light of what is already known, thereby making them also an integral part of one’s body of knowledge.
Apperception differs from assimilation in implying that the mind responds to new facts, ideas, or situations when and only when it can relate them to what is already known.