Auto snap
The Auto-snap functionality lets you accurately snap elements to each other or to different zones of your page. When dragging an elements you will see red lines that show you the centers and endpoints of the other elements.
Enabling the auto-snap functionality:
By default the auto-snap functionality is disabled. To enable it click on the magnet button on the left side of the editor.
Note that the auto-snap functionality works for the whole account and not just for the website you are currently on. This means that you need to activate it just once and it will work on all websites that you manage.