How does a plug-in works?

These days i'm trying to play with plug-ins but i have a little problem.
Since i never played a plug-in before i don't know how they work.
Could somebody please help me?



You just need to put the plug-in in the plug-ins folder and open EV.

The space ships hung in the air much in the same way bricks don't.

Why is it that the more civilized the civilization, the more people they kill?