AutoCAD is a vector program that has both dimensions and directions.
So, it’s important to know the direction. To drag or write individual shapes The Axis system therefore plays a role in helping users to know which direction they are currently working in. AutoCAD starts with 2D (2D) work. The term 2D means seeing distances only on two sides: width and length.
The symbol (WCS: World Co-Ordinating System) is displayed in the lower left corner of the program as the two axes are X and Y as shown in Fig 1.
But in reality, we live in a 3D world (3D), which requires another axis. Representing the height, that is the Z axis. But when we look at it in 2D, the Z axis will be directed towards us.
Theoretically, the Z axis is invisible. If we want to see the Z axis, we have to change the angle of view from 2D to 3D, so the Z axis will be revealed.