This might be a weird question but what is the right way to think about how images are projected onto the screen?
if we have an image already on the screen and we render another image onto the screen does the new image go ON TOP of the old one, thus making the old one not visible anymore. or does it go behind the old one thus making the new one not visible till we clear the screen off of the old one. 
I used to think that the new image goes on top of the old one, however, after working with buffers for a little bit (ie BufferedImage and BufferedStrategy) I come to think that is not the right way it happens.
so can someone please clarify this matter
thanks