How do I make the screen color transparent?

How do I clear the screen color in order to get the screen transparent? Can I use glClearColor in this case? if so how do I set it? Is this screen transparency supported by OpenGL?

i don’t see what you really want.
but you may clear the color with a 4 values with something like that 0,0,0,0
this may make a transparent black screen

When we apply clear 0,0,0,0 we will get a black screen right? What I meant was we can get a transparent screen. Meaning that we can see the behind object.

As far as I know: not possible in OGL.