How to modify UCS in AutoCAD for 3d drawing (and restore to WCS)

How do you draw lines and circles and other things in AutoCAD that are not on the default XY plane? By modifying the UCS (user coordinate system), it can make drawing 3d shapes much easier. 0:00 Intro 1:00 Draw objects - example 1 1:20 Change the UCS of the drawing 2:38 Draw objects - example 2 3:30 Change the UCS of the drawing