Prototype Model is a Software Development Model that is used when the customer is not completely sure or aware of how the requirements for an end product. So in this model, a prototype of the end product is first developed by the developers and then tested and changes were made as per customer feedback until the customer is satisfied with the prototype.
Source: https://www.geeksforgeeks.org/difference-between-waterfall-model-and-prototype-model/?ref=rp