If the question is, "what is a saltwater lake in the sea (called)"? The answer is a lagoon
Lagoon
Saltwater is a solution because you can get fresh water and some salt and mix it and then you get saltwater.
Saltwater
salt
lagoon if it is land locked saltwater
Rain water is fresh water and does not have salt. Saltwater is not fresh and does have salt.
Salt water
The fresh water.
fresh water
Freshwater
NO they can not.