Streams are bodies of water that have a current; they are in constant motion. In streams, water always flows downhill, but the form that downhill movement takes varies with rock type, topography, and many other factors.
A river is a natural stream of water, usually freshwater, flowing toward the ocean, a lake, or another stream. Usually larger streams are called rivers while smaller streams are called creeks, brooks, ect. But there is no general rule that defines what can be called a river..
A river and a stream are both fast moving bodies of water but the river is called a river because it is larger, deeper, longer, wider, ect.
You can only contrast how big, deep, they are. Or what kind of wildlife they hold attract.
You can compare them because they are both bodies of water that have a current.
