What is the difference between the riverbed and the river system?

Riverbed:

The riverbed is the channel that a river flows through. It includes the bottom and the sides of the channel.

River System:

A river system includes the main river and all of its tributaries (smaller rivers and streams that flow into the main river). It encompasses the entire area drained by the river and its tributaries.

Answer: The riverbed is the physical channel, while the river system includes the main river and all its tributaries, forming a drainage basin.