An Effective "UDL"?

This is a bit of a new title for a learning strategy in my opnion, a "UDL"? Hmmm. Well, from the way I understand this, there are things like scaffolding, "time management" and many of those other strategies we use so often as teachers.
Maybe in American schools there is a different name for them? A teacher made a video and posted to youtube, their "UDL's" in a couple lessons of Mathematics at the 8th grade level. Interesting is normally what I would say, expect the video didn't clearly introduce what was happening.
Nonetheless, for the course we are asked to discuss which of the "UDL's" we feel is most effective/important.

To be honest for a 7/8 class an exit ticket is most important I feel because a class will always be worried about social dynamics and depending on groups (as they are situated), there may be students who are pretending to listen and are good at tuning out/selective hearing. Exit tickets are private and a bit more personal so as long as the teacher has a good rapport with the students; it is extremely beneficial.