The computer screen is a 2D environment and when working with 2D graphics whe working with 3D and software applications, the cartesian co-ordinate system is used to create the illusion of working with 3D space.A french mathematician and philospher Rene Descartes created the system.in the 2D system there are only 2 axis the X axis and the Y axis the X axis is horizontal and the Y axis is vertical they form the XYplane.The point where X and Y meet is called the origin or the 0 axis.early in the 19th century the Z axis or the 3rd dimension was added.The 3rd axis (Z) is the viewpoint that adds the third dimension and adds depth.The format for a point is (X,Y,Z). In the 3d Design program 3DS Max the views are based on the cartesian system are called viewports. The views are classified as orthographic and they are only 2 axis in the view port while perspective shows 3 axis in the viewport.top, front and left are orthographic view ports.