Generic geomorphology concept articles that describe a kind or class of landform rather than one specific named place, gathered here from across this category's formerly mixed subcategories so a reader looking for the concept behind a named feature (what a drumlin, an esker or a floodplain actually is) can find it directly. Includes glacial and periglacial landform types (Drumlin, Esker, Moraine, Pingo, Kame, Rogen Moraine), fluvial and coastal landform types (Floodplain, Levee, Oxbow Lake, Beach, Spit, River Delta), arid and aeolian landform types (Dune, Barchan, Erg, Loess), and general erosional and structural landform types (Cliff, Gully, Peneplain, Terrace, Waterfall, Isthmus, Peninsula). Belongs here: any article whose own subject is the landform TYPE itself, described in the abstract or by a representative process, not a single named instance of it. Does not belong here: a specific named place that instantiates one of these concepts (a named drumlin, a named moraine, a named floodplain), which stays classified by its own kind and location elsewhere in this category.