Filters vs. Effects?

What's the main difference between the two? Effects are more flexible, allowing you to edit the effect through the Appearance palette (Window>Appearance), but they require more memory and processor power. Filters are "permanent" (although you can choose Undo from the Edit menu), but typically they don't take as long to process. In our example, we first applied the Roughen filter (Filter>Distort>Roughen), and then we applied the Roughen effect (Effect>Distort & Transform>Roughen), which is editable in the Appearance palette.