Constraints is the most commonly misunderstood feature in MS Project and understanding how to use constraints is one of the things that separates the amateurs from competent users that are in the know.  Key 3 Constraints, thus becomes an absolute cornerstone of knowledge for any practitioner of MS Project that truly wants to understand and use MS Project effectively. In combination with Key 1 (Navigation) and Key 2 (Task linking courses) you have built the foundation to understand Constraints!  Get ready to go and tackle one of the most difficult aspects of MS Project---but with videos that provide a clear explanation you can get your head around and conquer!