Communication between CUPS & native linux printer driver.

[Ved Prakash]

hi all,
  As per my understanding CUPS acts as an intermediate between application(print task) & linux printer driver "usblp". Am i right??
Or it really contains drivers?? Think every thing from usb printer point of view.
  Actually i want to conclude that
  1. Whether CUPS contains drivers which is used to communicate between application & printer without using usblp.
  2. If yes where they are stored & how they work??
  3. One more thing suppose i am going to use a brand new vendor usb printer then only ppd file of that printer is enough to store in /usr/share/cups/model as i have read in on of the reply in this forum.

Thanks in advance......