SEM is short for search engine marketing, or pay per click marketing. This allows you to place your ad at the top of Google in an online auction where you pay every time someone clicks your ad for a specific word. Search engine marketing includes the promotion of websites by auctioning the position of the top 3 ads as well as ads on the bottom of the page. This is primarily done through paid advertising in a pay per click environment.
Search engine optimization is the result of adjusting, optimizing, and rewriting website content to follow Google best practices site architecture to achieve a higher ranking in search engine results pages.
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