Editing Landform (section)

== Hierarchy of classes ==
[[File:1 li jiang guilin yangshuo 2011.jpg|thumb|[[Tower karst|Karst tower]] landforms along the [[Lijiang River]], [[Guilin]], China]]

{| class="wikitable"
|+ Landforms by order
|-
! Order !! Landforms
|-
| First || [[Continent]]s and [[ocean]]s
|-
| Second || [[Hill]]s, [[mountain]]s, [[plain]]s, and [[plateau]]s
|-
| Third || [[Lake]]s, [[summit|mountain peaks]], [[dune|sand dunes]], [[valley]]s, and [[waterfall]]s etc.
|}

[[Continent]]s and [[ocean]]s exemplify the highest-order landforms.{{citation needed|date=October 2022}} [[Glossary of landforms|Landform elements]] are parts of a high-order landforms that can be further identified and systematically given a cohesive definition such as hill-tops, shoulders, [[Saddle (landform)|saddles]], foreslopes and backslopes.

Some generic landform elements including: pits, peaks, channels, ridges, passes, pools and plains.

[[Terrain]] (or ''relief'') is the third or vertical dimension of ''land surface''. [[Topography]] is the study of terrain, although the word is often used as a synonym for relief itself. When relief is described [[underwater]], the term [[bathymetry]] is used. In [[cartography]], many [[Cartographic relief depiction|different techniques]] are used to describe relief, including [[contour line]]s and [[Triangulated irregular network|triangulated irregular networks]].

Elementary landforms (segments, facets, relief units) are the smallest homogeneous divisions of the land surface, at the given scale/resolution. These are areas with relatively homogeneous [[morphometric]] properties, bounded by lines of discontinuity. A plateau or a hill can be observed at various scales, ranging from a few hundred meters to hundreds of kilometers. Hence, the spatial distribution of landforms is often scale-dependent, as is the case for soils and geological strata.
[[File:Erg Tiffernine.tif|thumb|[[Erg (landform)|Erg]] Tiffernine in [[Algerian Desert|Algerian Sahara]]]]
A number of factors, ranging from [[plate tectonics]] to [[erosion]] and [[deposition (sediment)|deposition]] (also due to human activity), can generate and affect landforms. [[biology|Biological]] factors can also influence landforms—for example, note the role of [[vegetation]] in the development of [[dune]] systems and [[salt marsh]]es, and the work of [[coral]]s and [[alga]]e in the formation of [[reef|coral reefs]].

Landforms do not include several man-made features, such as [[canal]]s, [[port]]s and many [[harbor]]s; and geographic features, such as [[desert]]s, [[forest]]s, and [[grassland]]s. Many of the terms are not restricted to refer to features of the planet [[Earth]], and can be used to describe surface features of other planets and similar objects in the [[Universe]]. Examples are mountains, hills, polar caps, and valleys, which are found on all of the [[terrestrial planets]].

The scientific study of landforms is known as [[geomorphology]].

In [[onomastic]] terminology, [[toponyms]] (geographical proper names) of individual landform objects (mountains, hills, valleys, etc.) are called ''[[Toponymy|oronyms]]''.{{sfn|Room|1996|p=75}}