A stream, stream, riera, rivera or ravine[note 1]​ is a natural current of water that normally flows continuously, but unlike a river, has a low flow rate ("Flow (fluid)"), which can even disappear in the dry season, summer or winter, depending on the rainy season for its existence. In the case of having a very low and sporadic flow, it is preferable to use the torrent name "Torrente (hydrography)"), ravine or ravine.

F. J. Monkhouse gives three meanings of the term stream:.

A stream may have, especially in its mountainous course: a reception basin, a drainage channel and a discharge cone (see the term torrent).

On the other hand, a ford "Ford (place)") is the place where the stream is so shallow that it can be crossed on foot or is used for bathing. They call these fords baños, bañaderos, balnearios "Balneario (Latin America)"), crosses or steps in some South American countries. When it is very narrow it is called ravine and when the water is dammed naturally it is called pool or lagoon and if it is artificial dam, dam or reservoir.

Like rivers, they can flow into the sea, into a lake or into another river, in which case they are called its tributaries.

In some South American countries, some "streams" are true rivers, which can become very large and even navigable. Also in South America and specifically in Barranquilla, streams of rainwater that run over city roads are called “streams,” generally at high speed, which significantly hinders mobility and reduces the safety of pedestrians.

• - Rambla (geomorphology) "Rambla (geomorphology)").

• - Torrente (hydrography) "Torrente (hydrography)").

• - Quebrada, geographical feature.

• - Wikimedia Commons hosts a multimedia category on Arroyo.