What are the advantages of using a content management system (CMS) for managing a website? Your response should contain at least 5 sentences. Highlight at least 2 sections in your answer with markdown, i.e. *highlighted section*. Include keywords *efficiency*, *flexibility*, *user-friendly*, *content updates*, *SEO* in the response. At the end of your response, please explicitly add a postscript starting with *P.S.*.
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