Object snaps include a visual aid called AutoSnap™ to help you see and use object snaps more efficiently. AutoSnap displays a marker and a tooltip when you move your cursor over an object snap location.
AutoSnap consists of the following snap tools:
The AutoSnap markers, tooltips, and magnet are turned on by default. You can change AutoSnap settings on the Drafting tab in the Options dialog box.
Use AutoSnap to Confirm or Change an Object Snap
If you have set more than one running object snap, you can press TAB to cycle through all the object snap points available for a particular object.