What are snapping points
The following figure illustrates the three different types of snap points.:
Middle and Intersection Snap Points:
When both the Item Snap and the Collision buttons are activated and you move one item near another item, the middle or intersection snap points of the items are displayed. If you click while these snap points are displayed, items will snap to each other's corresponding points. These snap points appear only when one item is moved or rotated near another item and disappear once the item is placed.
Center Snap Point:
When the Item Snap button is activated and the Collision button is deactivated or bypassed, the center snap points can be displayed. That is, when you move one item to the center of another item, the center snap point of the static item is displayed. If the moving item's "center" goes by a snap point of a static item, the moving item's center snap point is displayed. The center snap point appears only when an item is moved or rotated in another item and disappears once the item is placed.
How to make items snap
Click the Item Snap button in the Work Area toolbar to enable or disable it. When Item Snap is enabled and you move, rotate, or drag one item near another item, the items' snap points are displayed. If you click while these snap points are displayed, the items snap to each other's points and the snap points then disappear. The default snap distance is 3 inches.
When Item Snap is disabled, items do not display their snap points while they are being moved, dragged, or rotated. Also, items will not snap even if they are placed within the snap distance specified in the Work Area Settings.