The document defines and provides examples of different landforms including rivers, lakes, mountains, peninsulas, and coasts. Specifically, it notes that a river is a large flowing body of water that empties into an ocean or sea, a lake is a body of water surrounded by land, a mountain is a tall natural elevation higher than a hill, and a coast is the edge of a continent or island bordering the sea. The document aims to teach about different types of landforms through their definitions and examples.