How to "center pivot"?

How can I “Center pivot” of an object?

In this image, the orange dot, is the pivot of the small panel. How can I bring back the pivot to the center of the object.

In Object Mode, select the object and click on the Origin button in the Toolshelf (panel to the left of the 3D View)
Then in the popup select “Origin to Geometry”, or if you want the origin point on the location of the 3D Custor, select “Origin to 3D Cursor”

Thank you!

One quick question, what’s the difference between, “Origin to Geometry”, and “Origin to Center of Mass”?