What are the differences between a harbor and a port?

Answer 1

Harbor has multiple meanings, one is the same as port - as in a good place to park a ship (moor or mooring), another is to seek safe harbor from enemies, this does not need to be on water. Water is a requirement for ship parking. Port also has multiple meanings, port the drink, an engine port - (hole or tunnel for water or fuel passage.) or port for ships, (a safe place to stop, park your ship or boat for protection from bad weather etc, this can also be called safe harbor.
The harbour is the body of water by the port.

The Port is the actual dock.

A harbour is a place where ships may shelter from the weather or are stored. Harbors can be man-made or natural. A man-made harbor will have sea walls or breakwaters and may require dredging. A natural harbor is surrounded on most sides by land.

Harbors and ports are often confused. A port is a man-made coastal or riverine facility where boats and ships can load and unload. It may consist of quays, wharfs, jetties, piers and slipways with cranes or ramps. A port may have magazine buildings or warehouses for storage of goods and a transport system, such as railway, road transport or pipeline transport facilities for relaying goods inland.

in short a port is used mainly for marine trading and a harbour is used as a parking space or a storage space for ships