Search engine marketing (SEM)
…is a form of Internet marketing that involves the promotion of websites by increasing their visibility in search engine results pages (SERPs) primarily through paid advertising. SEM may incorporate search engine optimization (SEO), which adjusts or rewrites website content and site architecture to achieve a higher ranking in search engine results pages to enhance pay per click (PPC) listings.
What is the difference between SEO and SEM?
SEM incorporates SEO.
SEM includes both paid search results (using tools like Google Adwords or Bing Ads, formerly known as Microsoft adCenter) and organic search results (SEO).