Rendering Key Frame Frequency

[CSCorbridge]

Curious...so you know how when you're about to render a video (e.g. .MOV format) and in the last dialogue box there is a field that prompts you to enter how often it will keyframe. What exactly does this do and how will it effect the render if at all when the values are changed? Is it supposed to match my FPS setting? I'm also wondering if I need to worry about setting a bit rate limit on that same prompt menu, I don't know what that's for either, is it important for anything? Forgive my ignorance, I'm still learning bits at a time, and have had a difficult time figuring this one out.
-Casey

[slowtiger]

Just leave that empty.