Object snapping makes one point or object snap towards another when one of them is moved. Object snapping only takes place when it is enabled by Snap to Objects on the Window menu or by the Magnet button on the Standard Control bar. See Object Snapping Overview for more details. You can specify separate snapping distances for point and lines. This makes it possible to snap two points together precisely.
The small magnet icon on the status line lights up and a magnet appears on the mouse pointer when the point or object being dragged has been snapped magnetically to a stationary object.
Guides can also be made magnetic using Snap to Guides on the Window menu.