What is the difference between border and frontier?

Can you please explain the difference between the terms "border" and "frontier" in a clear and concise manner? I understand they both relate to geographical boundaries, but I'm curious about the specific nuances that distinguish one from the other. Is there a historical context that helps to clarify the distinction? Additionally, are there any scenarios where the two terms might be used interchangeably or where one is more appropriate than the other? Thank you for your assistance in clarifying this topic.