For a vast majority of customers, their first task when coming to an e-commerce web site is finding something to buy. They might want to buy a camera, a book, or a piece of jewelry. If you were to walk into a store with relatively few items for sale, the task of finding what you want might be easy. If, however, the store you walk into has thousands of shelves and hundreds of thousands of items for sale, finding what you want presents its own challenge. In such a store, a good store owner would arrange items in a way that would help customers quickly find the items they want to buy. Such is the case with Amazon.

Amazon has literally hundreds of thousands of items for sale. Product Advertising API operations and response groups give you the tools you need to find the items in the store that you want quickly. Before understanding the search mechanisms that Product Advertising API operations provide and the filtering mechanisms that Product Advertising API response groups provide, it is important to first understand the way in which Amazon groups items for sale.