What type of relay do I need?

[Kentish]

I'm looking at switching off some lighting on the car when my headlights are switched on.

So I need a relay with a circuit that "opens" when I send 12v to it.

Is this called something in particular or is it just a power relay like this one?

http://www.maplin.co.uk/Module.aspx?ModuleNo=6436

Cheers,
K