What is a reference array?

In a script Im building I need a reference array. I know how to make it and use it but I dont really understand the function of it, what is the difference with a list? Ive been googling but I`m not finding a good explanation.
Maybe someone can explain?
Wouter Hilhorst

Arrays, ArrayLists and Lists are similar. Their use is dictated by implementation. See here https://stackoverflow.com/a/32020072.

Hi Tomasz,

Thanks for your reply!
Revit is asking for a reference array when placing dimensions via the api.
I was just wondering why, now its more clear!

Wouter Hilhorst