when you buy cable brakes on a bike, do you buy one or two?

[justin green]

I have a schwinn continental and I want to buy these fun brakes with pink housing. I don't know if I need to buy two or one because do I need to buy a set for the front and the back? or just one set will have the cable for both? this is the link for the cable I want.

http://www.junkyrustybikes.net/product_info.php?cPath=67_68&products_id=54