what is the meaning of 2+ keywords and what is the ten levels of proximity ? and what keyword prominence means ?
What do you mean? Some keywords are single words - while others are phrases. brochures and brochure printing and full color brochure printing would all be different. You could still pop up in search results for having brochures. But if you didn't rank for that keyword you could still rank for exact match phrases and close match phrases that include those words like full color brochure printing. Proximity means how closely together in the word structrure of an article etc. Prominence means to be obvious or conspicuous. How obvious is it that your keyword is a keyword and not just a random word used to support your keywords. and then, whats the proximity of the support words - should they be used in created phrases. (because google will pull keyword phrases out of your site that maybe you hadn't even intended. ) Do you use Google webmaster tools? Haven't you ever noticed ranking for odd combination of words - I think what you are wondering is... the process that Google might use to create those types of word phrases or collection of words?
The specific location of keywords in a web page. The higher up in the page a particular word is, the more prominent it is and thus the more weight that word is assigned by the search engine when that word matches a keyword search done by a search engine user.