Mouseover Macros, how do they work?

[warlockbell]

When you create a mouse over macro, what exactly does it do? I found a particularily helpful looking macro for PvP, but I have no idea what it does.

/cast [target=mouseover,exists][] Fel Flame

What does this macro do? What happens when you 'mouse over' a target?

Thanks!

[malkara]

Basically, mouse over means mouse over their physical form in the game world, or their portret. If you've got them turned on, it can also be used on nameplates. When you press this button while your mouse is over any of the before mentioned places, the spell casts on that person, instead of your target/yourself.

[BaddyMcBad]

That specific macro will cast Fel Flame at your mouseover if it exists, and if it doesn't it will cast at your target.
For future reference you can use http://www.macroexplain.com/ to find out what other macros do.