Search Engine Marketing, commonly abbreviated as SEM, is the process of gaining traffic and visibility from search engines through both organic and inorganic or paid and unpaid approaches. From textbook definition – Search Engine Marketing or SEM is a form of Online marketing that entails the promotion of websites by increasing their visibility in search engine results pages, also known as Search Engine Results Pages, through optimization and advertising. Search Engine Marketing may use search engine optimization SEO, which adjusts or rewrites website content to attain a higher ranking in search engine results pages, or use pay per click listings. Originally called Search Engine Marketing , the shorter phrase SEM is now often used as the umbrella term over SEO and SEM. On the whole, Search Engine Marketing is all about attracting traffic and business leads from search engines through online ads and other promotional gimmicks. Generally, giant search engines such as Google, Yahoo or Bing run PPC (Pay per click) advertisements and place ads based on specific keywords. Search Engine Marketing, if applied in an appropriate way, is the most dominant and influential tool.