What is the signficance of EA, ED, ED2, RD, REA, SCEA etc?

No doubt the same for D. I just wanted to make sure I understood what all these different types of applications mean, and it clearly varies by school.

I guess I will make one observation: all of this just complicates things for the kids and are designed to enhance the school. It just adds a layer of complexity that wasn’t there when I applied decades ago. I suppose it does give some benefits to the applicants, but these new-fangled inventions seem to benefit the colleges far more.