I'm doing software engineering for a living. And also I'm playing amateur rugby. And one of the things that makes me laughing out of loud is Scrum (in the context of software development) which is one of the magic Agile terms:
They called this the holistic or rugby approach, as the whole process is performed by one cross-functional team across multiple overlapping phases, where the team "tries to go the distance as a unit, passing the ball back and forth".
Probably, the guys that named it scrum were keeping in mind the maul - the action when the ball is held by one or more opponents, and one or more of the ball carrier's teammates bind on the ball carrier. Once a maul has formed other players may join in but, as in a ruck, they must do so from their own side.
So, this is the maul:
And this is what actually the scrum is - a way of restarting the game safely and fairly after a minor infringement:
Scrums are one of the most dangerous phases in rugby, since a collapse or improper engage can lead to a front row player damaging or even breaking his neck.
Now you know the difference.