Main Difference
The main difference between Valley and Canyon is that the Valley is a low area between hills, often with a river running through it and Canyon is a deep ravine between cliffs.
Valley
A valley is a low area between hills or mountains often with a river running through it. In geology, a valley or dale is a depression that is longer than it is wide. The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys. Most valleys belong to one of these two main types or a mixture of them, (at least) with respect to the cross section of the slopes or hillsides.
Canyon
A canyon (Spanish: cañón; archaic British English spelling: cañon) or gorge is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic timescales. Rivers have a natural tendency to cut through underlying surfaces, eventually wearing away rock layers as sediments are removed downstream. A river bed will gradually reach a baseline elevation, which is the same elevation as the body of water into which the river drains. The processes of weathering and erosion will form canyons when the river’s headwaters and estuary are at significantly different elevations, particularly through regions where softer rock layers are intermingled with harder layers more resistant to weathering.
A canyon may also refer to a rift between two mountain peaks, such as those in ranges including the Rocky Mountains, the Alps, the Himalayas or the Andes. Usually a river or stream and erosion carve out such splits between mountains. Examples of mountain-type canyons are Provo Canyon in Utah or Yosemite Valley in California’s Sierra Nevada. Canyons within mountains, or gorges that have an opening on only one side, are called box canyons. Slot canyons are very narrow canyons that often have smooth walls.
Steep-sided valleys in the seabed of the continental slope are referred to as submarine canyons. Unlike canyons on land, submarine canyons are thought to be formed by turbidity currents and landslides.
Valley (noun)
An elongated depression between hills or mountains, often with a river flowing through it.
Valley (noun)
The area which drains into a river.
Valley (noun)
Any structure resembling one, e.g., the meeting point of two pitched roofs.
Valley (noun)
The internal angle formed by the intersection of two sloping roof planes.
Canyon (noun)
A valley, especially a long, narrow, steep valley, cut in rock by a river.
Valley (noun)
a low area of land between hills or mountains, typically with a river or stream flowing through it
“the valley floor”
“the Thames Valley”
Valley (noun)
an internal angle formed by the intersecting planes of a roof, or by the slope of a roof and a wall.
Canyon (noun)
a deep gorge, typically one with a river flowing through it, as found in North America
“the Grand Canyon”