is the process by which soil and sediment are transported from one location to another. Examples of erosion are rivers, wind, ice, and snow.
the continuous movement of earth's water from the ocean to the atmosphere to the land back to the ocean. The water cycle is driven by energy from the sun
a stream that flows into a lake or into a larger stream is called a tributary
watershed (drainage basin)
the area of land that is drained by a water system
watersheds are separated from each other by an area of higher ground called a divide