Understanding the e:, evt: etc in a function

programming flash
1

Hi,

I have been using functions since the first day I started using Actionscript 3.0 in fact I think is one of the first things I learned but I guess I never had a good understanding as to why the use of the “evt:” I know this is probably something I should already know but as you can see I don’t (shame on me).

Can someone explain me what is the purpose of the evt: , e: and event:(I guess this can be anything)?

addEventListener(MouseEvent.CLICK, someFunction);
  function someFunction(e:MouseEvent):void{}

I understand the need of MouseEvent since we need to tell the function the type of event we are looking for but what is the “e” doing?

Is “e:” some sort of local variable that never gets referenced?

Can someone be so kind and give me a brief explanation, I want to have a better understanding and not just do it without having any idea why?

Thanks