That's a good question who is SEO GURU. Wondering if you want to ask something from that person, or you're asking for curriosity purpose?
Your second question, you probably mean how can SERP latest updates related to SEO. The answer is the following, search engines have certain robots which crawl the websites and bring the results to SERP. The position of the site in SERP really depends on many different factors that of course include how good is the site optimization done. If you currently optimized your site then web crawler will pick your latest changes and update SERP results based on certain keywords and key phrases. Hope I it helps.