Exemplar Model: This suggests people form categories based on all examples they have encountered rather than an average prototype. Like remembering every dog you've ever seen instead of just picturing one typical dog.
Stereotype:These are oversimplified generalizations about groups of people without considering individual differences. Like assuming all dogs behave exactly like your prototype dog does.
Semantic Network Model: This proposes concepts are organized within networks in our mind based on experience and knowledge. Imagine if each type of dog had its own web page linked from your main 'dog' page.