Snap to the grid, a curve, points, or a view plane

User Guide > General > Basics > Transforming objects > Align and snap >

When using the Move Tool and various creation tools, you can snap to existing objects in the scene.

To snap a move, press on the object you want to snap to (pressing just selects the object).

To snap to...	Hold	Or turn on this icon in the Status Line (toolbar)
Grid intersections	x
Curves	c
CV, vertex, or pivot	v
View plane

NoteIf you have snapping turned on and drag an arrow on the position manipulator (as opposed to the center), the manipulator snaps to the first available point along that axis.