And rainbow trout is a special name.

Salmon is a common name for some salmon, which originally refers to Atlantic salmon (Salmo salar) of the genus Salmon. With the development of aquaculture, merchants also refer to Pacific salmon (Oncorhynchus) and other fish as "salmon". For example, rainbow trout (Oncorhynchus mykiss) is a kind of cold-water pond fish culture of the genus Pacific Salmon, which is now called "salmon" by some merchants.

Extended data:

Salmon, also called salmon or salmon, is one of the more commonly used fish ingredients in western food. There are different kinds of salmon in different countries' consumer markets. Norwegian salmon is mainly Atlantic salmon, Finnish salmon is mainly large-scale red-fleshed rainbow trout, and American salmon is mainly Alaska salmon.

Salmon generally refers to the fishes of the genus Salmonidae, and there are many species, such as salmon produced in northeast China and humpback salmon.

Rainbow trout, Oncorhynchus mykiss (Walbaum,1792), is a kind of cold-water pond fish of the genus Pacific salmon. Rainbow trout is an important cold-water fish widely cultivated in the world. Mature individuals is named because it has a brown-red longitudinal stripe along the lateral line, which looks like a rainbow.

Native to the north of North America and the west coast of the Pacific Ocean, it mainly lives in low-temperature fresh water, which requires high water quality in aquaculture waters. Rainbow trout is a kind of edible fish, which has been transplanted to many countries, but has become an invasive species in some areas.

References:

Baidu encyclopedia-salmon