Everything depends on the search engine and the search terms you use. The Internet is a huge noticeboard; lots of stuff on it is merely ads and catalogue prices etc. The search terms are collected by the search engines by examining terms inserted by the web page author. There is no guarantee that the web pages are really "about" the term you specify, though they should be roughly related in some way.
Use the Settings to be demanding about what you download, e.g. in requiring certain words or phrases to be present.
See also: Display