Introduction to  Search Engine Optimization 
What is Search Engine?
A program for the retrieval of data, files, or documents from a database or network, esp. the Internet.”
Examples: Google, Yahoo, Bing, Ask, MSN
What is search Engine Optimization?
SEO is the process of improving the visibility of a Web site or a Web page in the search engines  for people who are looking for your product or service via search engines.”
What is Ad ward?
—Search engines make money by running search related ads alongside the organic search engine results .
—The search engine makes money every time someone clicks on one of these ads.
—This technique is known as pay-per-click advertising.
—Advertisers pay or bid for placements in the search results for keyword phrases of their choice.
—Each time a user clicks one of the ads in the search results it costs the advertiser – this payment is made directly to the search engine.
How Google Work?
—Google has a Web spider.
—Automated software that crawls the Web and indexes all pages it finds
—Google has a ranking algorithm.
—Complicated logic that ranks the sites and pages based on content, links and other factors
—Google PageRank depends on the quantity and quality of the external links to it (backlinks)
—Still, no one knows how exactly Google works.
—Its search algorithms change every day