How can I record game footage?

I am trying to record game footage from a Macintosh platform. Is there any in Unity way to do this ? If not what is the best way to record game experience to show a client?

I personally prefer the pro version of Quicktime. I haven’t been able to get screen caps with a higher frame rate. Completely worth the $29.99.

Sorry to be slow on understanding but can you describe the process for using quicktime to capture game-play in UNITY?