The major function of the Amazon River in South America is its role as a critical waterway for transportation, ecology, and climate regulation. Spanning over 4,345 miles, it is the second-longest river in the world and the largest by discharge volume. The Amazon provides essential resources for millions of people living along its banks, including fishing, agriculture, and transportation. Its vast rainforest ecosystem plays a crucial role in carbon storage and oxygen production, significantly impacting global climate patterns. The river's health is vital for the biodiversity of the Amazon Basin and for the Earth’s overall ecological balance.