Object snaps included with AutoCAD enable you to specify precise locations for objects.
AutoCAD Mechanical toolset extends this capability by enabling you to save up to four sets of object snaps and enabling you to switch between snaps in the middle of a command. The program activates saved object snap settings, referred to as Power Snap settings, when you start the AMPOWERSNAP command.
Power Snaps provide more snap options than AutoCAD Object Snaps. They also give you the ability to set filters so that snap ignores inappropriate objects. For example, filters can be set such that drawing tools do not snap to entities such as dimensions, while you are drawing.