MCP vs RAG: How do they compare? And which is better?

MCP (model context protocol) has become the new hot term in the LLM world, and is useful for adding all kinds of context to your prompt. But isn't that what RAG was for? What's the difference between these two technologies? What is RAG? https://youtu.be/BxTP6b7VPnE What is MCP? (Fly.io channel) https://youtu.be/74c1ByGvFPE