The UCS (User Coordinate System) is the system in which you are working. By default, it is located to coincide with the WCS, but it can be moved. UCS axes can be displayed from Program Setup, and they appear wherever the origin is located.

When using the 3D Selector, the selection shell local menu and Inspector Bar provide two options that relate selected objects to the UCS (see 2D - 3D Selector).
Set UCS by Selector: Moves the UCS origin to the selection reference point.

Set Selector by UCS: Moves the selection to the UCS origin (similar to the Place on WorkPlane option for 2D objects).

Note: The 2D Selector always moves the UCS (Workplane) to the selection.

Browser not supported