Product Advertising API
Developer Guide (API Version 2013-08-01)

Browse Nodes and Search Indices

A search index is a more general classification than a browse node. For example, one search index is Books. A browse node in that search index can be Harry Potter books.

There can be many browse nodes in each search index. Some Product Advertising API search operations require a search index to limit the scope of the search. Specifying a browse node and a search index returns more targeted search results. For example, an ItemSearch request in the Books search index for book titles and descriptions that contained the word "dragon" can return thousands of titles. The same ItemSearch request with the Harry Potter browse node specified returns only Harry Potter books that have dragons in the titles or descriptions.