What isa z-buffer and how is it used in computergraphics?

Answer: Z - buffer is the technology that is used in computer graphics field, it is also known by the name of depth buffering. It is used for checking of the visibility of a object in particular scene. It determines the object's position whether are in front or backward with respect to each other in a 3D view. It is used when there is an object that has been projected on the screen, then depth or z-value of the produced pixel gets stored in the z-buffer.