Snaps help you precisely control the dimensions and placement of objects when you create them or transform them. There is also a Spinner snap for controlling the entry of values.
You can use objects within an XRef scene as snap references.
The snap commands listed following and described in this section are found on the main toolbar (except for Ortho and Polar; see their topics for details). They’re also available from the Grids And Snaps submenu of the Tools menu with the Default menu system, or of the Scene menu with the Alt menu system.