I am a little confused. I always thought you were only allowed to apply ED to one school only. However, when I read some ED decision threads, people also write down other colleges that accepted them - how does that work? So can you apply ED to many schools? if not, how is it possible that they are getting offers from other unis on December?
Some schools have non-binding early action notification or very early rolling admissions which give results quickly. Or people are sometimes stupid or attempting to cheat the system by applying to multiple ED programs.
You can apply to one ED program and other EA and rolling programs – this is allowed.
(caveat: some schools have Restricted Early Action which prohibit secondary ED or EA applications. It gets complicated)
You can only apply ED to one college but you can apply to rolling admission colleges and some EA colleges at the same time. So students can get several acceptances in December. However, once you’ve accepted an ED offer, you must withdraw applications from all other colleges. Hope this helped to explain.
REA and SCEA are the same as Tom says. In general, if you apply SCEA or REA, you’re forbidden from applying to any ED (binding) program or another EA program with a private school. Please read your target school’s policy – they differ somewhat from school to school