Search Engine Marketing (SEM) is a strategic form of online marketing. Like Search Engine Optimization (SEO), SEM to helps to give webpages better visibility on search engine results. However, SEM differs from SEO in being a form of paid advertising and functions under a pay-per-click (PPC) pricing model. SEM may involve rewriting website content and changing website architecture to achieve a higher listing in search engine results pages. Advertisers pay when users divert their browsing to click on these marketing messages and move in the intended direction of the advertiser.