Plug-in, module, add-in or extension?

Hello all,


I made a simple plug-in framework in vb .net and it works great. But then I thought: Why did I named it "plug-in" and not "add-in" or "module" or something else.

Is there a difference between a plug-in, module, add-in, extension, etc. Are they all the same or does a module mean something else then a plug-in? Cause some applications/websites use the term plug-in but others add-in or module.

Not really an life depending question, but I was wondering about it. Does anyone know the answer?


Greetings,
Jelle

See http://en.wikipedia.org/wiki/Plugin and then probably relax.

I make distinctions myself but it seems to be very subjective.