Entering the conversation revolves around the idea that all topics are surrounded by preexisting conversations about that topic. Other authors have already established a context for a particular topic, and it's important to situate your own ideas in this context, whether you're agreeing or disagreeing with an existing idea, making a commentary on existing ideas, or presenting a new perspective.
Watch this video for an overview of what it means to enter/join the conversation from the perspective of research and writing.