Determining which object is topmost (zorder)

Support Basics & Interface
#1

In Blender, how do we determine which objects appear topmost and bottommost if 2 or more objects overlap each other? Is there a way to make Object A topmost, Object B below it, Object below Object B and so on.

Is there a way to tell Blender which one should be on top?

(In application development tools, there usually is a mechanism called zorder where you enter a number (integer), the higher the number the higher the object in terms of the view hierarchy. Is there a similar mechanism in Blender?

#2

zOrder is used in programs that are actually 2D like Inkscape, Corel Draw! or Powerpoint for instance.
Blender is a 3D program, when you can use 3 Dimensions what use would a zOrder be, or more specific what do you want to acomplish?
The only thing slightest similar is the zOffset for materials.