Thanks so much for reading @gentleshaid. To answer your questions ;
A swamp is just a type of wetland; there are four types: Bog, Fen, Swamp and Marsh. Maybe I'll do another post on them
On the type of water found in wetlands, it depends on the source of water to the wetland.
If the wetland is found around a freshwater body, it's most likely a freshwater wetland and if it's around a brackish water body, it'll be a blackish wetland.
The source of water also determines the type of wetland it'll be (bog, fen, marsh or swamp)
- I referred to moss and grass as being dominant in wetlands, there are definitely a whole lot of other plant species that can be found here