Each prompt consists of a sequence of messages. Each message is of type to system, user, or assistant.

A user message is a question or set of instructions to AI from a human.

An assistant message is a response from AI.

A system message is a set of general instructions to the AI assistant - e.g., "I'm playing a game where every time I respond, I must provide an answer and then follow up with my own question related to science, theology, or history."