How do search engines find relevant content?

Question

How does Google find relevant content when it\'s parsing the web?

Let\'s say, for instance, Google uses the PHP native DOM Library to parse content. What methods would t

Answer 1

I would consider these building the code

• Check for synonyms and acronyms
• applying OCR on images to search as text(Abby Fine Reader and Recostar are nice, Tesseract is free and fine(no so fine as fine reader :) )
• weight Fonts as well(size, boldness, underline, color)
• weight content depending on its place on page(like contents on upper side of page is more relevant)

Also:

• An optinal text asked from the webmaster to define the page

You can also check if you can find anything useful at Google search API: http://code.google.com/intl/tr/apis/ajaxsearch/