Prototypes are typical, highly representative examples of a concept that correspond to our mental image or best example of the concept.
For instance, although a robin and an ostrich are both examples of birds, the robin is an example that comes to most people’s minds far more readily. Consequently, robin is a prototype of the concept “bird”. Similarly, when we think of the concept of a table, we’re likely to think of a coffee table before we think of a drafting table, making a coffee table closer to our prototype of a table.