How is it that I type in a word and a search results page appears that helps me, even though the term itself doesn't appear in it? 

When you enter a search term, our intelligent search matches it against both the name of the existing categories and the terms associated with them. A category is linked with up to 25 keywords. For example, this includes synonyms, abbreviations, and similar words. Therefore, you may get a search results page even though your search term itself doesn't appear in it. As an example: You enter "helicopter" and products and companies with "helicopter" are displayed.