The Align tool moves or reshapes a curve or surface to achieve positional, tangent, or G2 curvature continuity with another curve or surface, and it offers G3 curvature continuity. It also provides a simplified interface, direct interaction through the use of manipulators, and superior output, compared to the Align 2008 tool.
If you have turned on Face selection in Preferences > Selection Options, the Align tool lets you select surfaces by clicking inside the wireframe. If a surface edge is expected, the tool automatically determines the closest edge to the mouse position.
This older version of the Align tool moves or reshapes two objects to achieve positional, tangent, or curvature continuity.