This question is asked to the experienced candidates by the recruiters in which they can define both separately as:
Social Marketing Environment is a conversational approach. As most of the social media conversations are not done for sales, so here professionals must try to recognize the exact need of his client and thereby to take him to his final and desired destination.
Social customer service environment is the ability to resolve patience, conflicts, and empathy. Here professionals must deal with their client in a way like they are their future customers. Try to resolve the issues and make them your all-time customers.