what is the vram and how can i use it??
The vram is the video ram. It’s the memory on your video board.
You use it each time you upload a texture, or a vertex array.
When you render a scene it’s rendered into a frame buffer that’s stored in vram.
a function like glReadPixels will read a bunch of data from the frame buffer on your vram and place it into a memory array designated by a pointer (the last parameter).
If you’ve ever programmed anything in OpenGL, chances are you’ve already used it 
i tought it was the video ram, but i read an info by farb-braush that said something like : yes we read a lot from the vram, so i tought it was something more complex, thanks!
Can’t be sure 'cause I’m out of context but maybe he was reffering to glReadPixels or some shaders?
mm i really dont know, ill try to look for the nfo file and post the url
can someone put an glReadPixels(); example or point me to a webpage with some examples on it, thanks!.
try to the OpenGL RedBook in the section “Read, Draw and Copy Pixels” or something like that
You can check it out on this website because a version of the Redbook is online
hope that helps