Large rivers are important components of continental landforms. Growth and development of early human civilization occurred in large fertile valleys. The origin, evolution, and physiography of many rivers depend primarily, but not always, on plate tectonics. Large rivers are characterized by low-intensity planforms. Flood pulses and sediment transfer in floods commonly travel both longitudinally and transversely in large rivers, whereas in smaller rivers floods commonly move downstream. Large rivers are huge systems that transfer water and sediment from the continents to the oceans. Many major rivers have undergone extremely large shifts in discharge due to climate change or meltwater floods at the end of the Pleistocene and in Early Holocene. The chapter also provides an overview of the key concepts discussed in this book.