Apps Running And Using Data When Not Open?

I'm new to android, i have a nexus 4. And notice that my data goes up pretty fast, i've changed my setting to where apps can only update when in a wifi zone, but was wondering. Lets say i had facebook opened at my house, i closed it by opening up my tabs that show my running apps and swiping it off to the side (i dont know if that ends the process or not) will facebook still remain open and use data when i leave my house? And i dont mean just facebook, like games and such aswell. If so, how do i prevent this to where i can make only certain apps run when im not on wifi.