Hi everyone. I am working my way through the Udemy course and PMBOK Guide, and am just not comprehending the differences between Cost Plus Award Fee and Cost Plus Fixed Fee contracts, and Firm Fixed Price and Fixed Price contracts. Both Cost Plus types cover costs plus an award fee - how are they different? Similarly, both Firm Fixed Price and Firm Fixed are a set amount regardless of cost - how are they different? I think I am missing the nuance here, and appreciate any help from the group. Thanks!