A more thorough explanation:

Definition: A river is a natural body of flowing water that empties into another body of water, such as a lake, sea, or channel. It can be classified as an international river, which flows through or between two or more countries, or a national river, which is wholly contained within a single country. A private river is one to which a riparian owner may claim ownership of the riverbed because the river is unnavigable or navigable only by vessels with shallow drafts. However, a navigable private river cannot be wholly owned by a private person and must remain open to public use for transportation and navigation.

Examples:

• The Amazon River is an international river that flows through Brazil, Peru, Colombia, and several other countries in South America.
• The Mississippi River is a national river that flows through the United States.
• The San Marcos River in Texas is a private river owned by the state, but it is open to public use for activities such as swimming, tubing, and kayaking.

The examples illustrate the different types of rivers based on their location and ownership. The Amazon River is an international river because it flows through multiple countries, while the Mississippi River is a national river because it is contained within the United States. The San Marcos River is a private river owned by the state, but it is still open to public use for recreational activities.