Many of the drafting commands in AutoCAD will only work in the horizontal plane, or in other words in the XY plane of the coordinates system. Even some parts of the 3D solid creation commands also have the same restriction (such as the base of the object when creating a pyramid or a wedge). While in the process of creating 3D models, you may need to draw a 2D shape on an elevated XY plane, a vertical plane, or even on the surface of another object. AutoCAD offers a set of tools that allows you to manipulate the coordinate system so you can align the XY plane as desired and hence the restrictions are eliminated.
In AutoCAD, there is an immovable reference coordinate system called the World Coordinate System (WCS). In addition to that, there is a User Coordinate System (UCS) that can be moved or rotated as desired. In this section, the tools related...