Are salmon and trout the same type of fish?

A freshly caught rainbow trout.

SHORT answer is no, they are not, however they are closely related.

Both salmon and trout belong to the family of salmonidae. Salmon are sea-going fish which spawn in freshwater at the end of their lives, whereas trout are mostly freshwater fish with a few exceptions such as the steelhead trout. The word trout is also used as part of the name of some non-salmonid fish such as the spotted seatrout or speckled trout.