Google indexes over 1 billion web pages and uses over 100 factors to rank search results. When a search is performed, Google uses its database to find relevant pages based on the search terms. It displays the URL, size, and date crawled for each result along with some displaying the cached version. Search terms can be refined using Boolean operators and search filters to focus on specific domains, file types, or words in the title or URL. PageRank also influences results by considering the number and quality of links to a page.