Provide a detailed response to the following query: "What are the key features of a smart home system?" Your response should contain at least 10 sentences. Highlight at least 2 sections in your answer with markdown, i.e. *highlighted section*. Include keywords *automation*, *security*, *energy efficiency*, *convenience*, *integration*, *voice control*, *remote access*, *monitoring*, *alarms*, *thermostats*. At the end of your response, please explicitly add a postscript starting with *P.S.*.

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