Check the JavaScript FAQ section, too: Here are some pretty good explanations and examples
Ok, why should you use this:
Suppose my script is running, and there are a couple of things (I'm, for instance, looping through a nodes list) I might be needing later on. That's why I might choose to do something like this:
for(var i=0;i
What this enables me to do is to prevent function arguments from being garbage collected. Normally, after a function returns, all its var's and arguments are GC'd. But in this case, the function returned another function that has a link to those arguments (it needs them), so they're not GC'ed for as long as aClosure exists.
As I said in my comment. Google closures, practice a bit, and it'll dawn on you... they really are quite powerful
