Bog, marsh, swamp, fen.

Often these words are used interchangeably, but in reality, each is its own type of wetland, which is a word used to refer to water-saturated landscapes. (Watch: What is a wetland?)

Photo of sunset over everglades


A marsh is a wetland that is continually full of water. If you have been to the Florida Everglades, then you have been to a marsh. These areas have soft-stemmed vegetation growing out of the water, because these specific types of plants thrive in soil that is completely saturated with water.

Photo of a swamp


A swamp is a type of wetland filled with woody plants. The soil is saturated during the growing season and has standing water other times of the year.

Photo of a bog


Bogs have spongy, peat-moss deposits. They have very acidic water, which is not good for plant growth, and they receive most of their water from precipitation — rain, sleet or snow — rather than from runoff from the landscape, groundwater or streams emptying into the bog.

Photo of a fen


Fens are peatlands and are fed by groundwater, which makes them less acidic than bogs and more nutrient-rich. They are home to sedges, grasses and rushes, because these plants love constantly saturated soil but not a flooded habitat. Over time, the peat in the fen builds up, and they feel almost bouncy when you walk on them.

(Fen, kame, esker — what do these words mean?)