Evaluating Content on a Web PageYou can think of this as the search engine performing a detailed analysis of all the words and phrases that appear on a web page, and then building a map of that data for it to consider showing your page in the results when a user enters a related search query.
What Content Can Search Engines “See” on a Web Page?
The information the search engine crawler is most interested in is in the HTML text on the page.
What search engines cannot see
Search engines will not recognize any text rendered in a image. The search engines are experimenting with technologies to use optical character recognition (OCR) to extract text from images, but this technology is not yet in general use within search.
Another type of content that search engines cannot see is the pictorial aspects of anything contained in Flash, so this aspect of Flash behaves in the same way images do. For example, when text is converted into a vector-based outline (i.e., rendered graphically), the textual information that search engines can read is lost.
One example of a technology that can present significant human-readable content that the search engines cannot see is AJAX. AJAX is a JavaScript-based method for dynamically rendering content on a web page after retrieving the data from a database, without having to refresh the entire page. In addition, until that input is received the content is not present in the HTML of the page, so the search engines cannot see it.
