Parameter Tree:
EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > SURFACE WATER > RIVERS/STREAMS

Definition:
River: A large, natural freshwater surface stream having a permanent
or seasonal flow and moving toward a sea, lake, or another river in a
definite channel. Stream: A body of running water moving under the
influence of gravity to lower levels in a narrow, clearly defined natural
channel. 


Reference:
Dictionary of Earth Science, 5th ed. 1997. Sybil Parker, ed. in chief.
McGraw-Hill.