Results are ranked according to the weight of the words that caused the match and the weight of the algorithm that generated the word. Word weights are generally determined by the importance of the word in a document. For example, words in the title of a document have a much higher weight than words at the bottom of the document.
Boolean searches are possible.
A Boolean search may use not , and , or and parentheses. The result will be one set of matches. It will ignore commas, single quotes and double quotes. This means that searching for phrases contained in quotes may yield unexpected results.