Dock, harbor, or pier?

What exactly is your question?

A harbor is water in a protected location where ships may get close to land.

A dock is anything provided for people or vehicles to get near ships. It is usually parallel to the land. A pier is usually perpendicular to the land.

A harbor is as JV states. In the Navy it was common to use dock and pier interchangeably. We were sailors, not grammarians.

The words are used interchangeably since they are all in the same place and nobody cares much. A dock might have piers attached, and a pier might have docks attached.

Yes!