What is the difference between a river, lake, swamp?

The river has a beginning (called a source) and an end (mouth), it flows into the sea. A lake and a swamp are bodies of water where water does not flow and is in a confined space. The water in the lake is clean, the bottom is either sandy or rocky, and fish is found in it. But the swamp sometimes even may not be noticed because of the vegetation on the surface, there are a lot of algae, and the bottom of the bog is a thick layer of peat. If the lake becomes shallow and overgrown with algae, then it may well turn into a swamp.