The course of a river is the route the river takes.

    The quantity of water in a river is called the flow.

    In some places, rivers have a lot of water in the autumn and in the spring. It rains more, and snow melts in the mountains.

    There are three parts in a river:

• The upper course: The river is narrow and there is less water. It flows very quickly.

• The middle course: The river is wider. There is more water. It does not flow as quickly.
  

• The lower course: The river is much wider and there is now much more water. It flows slowly.