A landing stage is a floating structure, usually a pontoon or a barge, which is secured to the shore by mooring chains. Small ships can dock against the landing stage. The landing stage is connected to the shore by a bridge.
A wharf is a wall built along a shoreline to receive ships from the sea directly, for facilitating loading and unloading. Since sea can have tidal variation, the wharf can be suitable only where the tidal variation is small. It is ideal for river transport.