Caviar is a food consisting of salt-cured roe of the family Acipenseridae. Caviar is considered a delicacy and is eaten as a garnish or a spread. Traditionally, the term caviar refers only to roe from wild sturgeon in the Caspian Sea and Black Sea(Beluga, Ossetra, and Sevruga caviars). The term caviar can also describe the roe of other species of sturgeon or other fish such as salmon, steelhead, trout, lumpfish, whitefish, or carp.

Source: Wikipedia