it's easier to show you then try to explain (a pictures' worth a thousand words

).
coilovers :
http://www.mmrusa.com/skunkcoils.jpg
they are adjustable, like the ones i have are adjustable between 0 to 4 inch drop.
lowering springs :
http://www.doctorimport.com/sprintsprings.jpg
are basically just shorter springs with a set height.