Come fly with me while I explain changing planes in AutoCAD. (Just step through this metal detector over here while I x-ray your bags.)
Okay, it's not that kind of plane. This section covers using the user coordinate system (UCS) to control the current working (or X,Y) plane. The UCS icon displayed either at the lower-left corner of the drawing window or at the origin (0,0,0) shows you the orientation of the current work plane and the positive direction of the Z-axis.
By default, the UCS icon is displayed in both 2D and 3D views. You can lose your bearings pretty easily when working in 3D, and I strongly recommend you keep the UCS icon in your sights at all times. If you don't see a UCS icon, you can turn it on from the Coordinates panel of the View tab. Click the button with the burned-out light bulb and choose either Show UCS Icon or Show UCS Icon at Origin.
In addition to controlling the display of the UCS icon, you can also tweak its size, color, and location using the UCS Icon dialog box. To display the UCS Icon dialog box, choose UCS Icon, Properties on the Coordinates panel of the Home tab.
In previous releases the UCS icon was merely a graphic indicator of the current coordinate system. If you set a new user coordinate system in model ...