Snapping helps with precise placement of selection edges, cropping marquees, slices, shapes, and paths. However, if snapping prevents you from correctly placing elements, you can disable it.
To temporarily disable snapping while using the Move tool, hold down Ctrl.
Snaps to guides.
Snaps to the grid. You cannot select this option when the grid is hidden.
Snaps to the content in the layer.
Snaps to slice boundaries. You cannot select this option when slices are hidden.
Snaps to the edges of the document.
Selects all Snap To options.
Deselects all Snap To options.
A check mark indicates that the option is selected and snapping is enabled.
If you want to enable snapping for only one option, make sure the Snap command is disabled, and then choose View > Snap To and choose an option. This automatically enables snapping for the selected option, and deselects all other Snap To options.