A fish fillet is a boneless piece of fish that has been cut from the side of the fish, removing the spine and most bones. Filleting involves cutting along the length of the fish to separate the flesh from the backbone, leaving a clean, skin-on or skinless portion of fish meat. Fish fillets can be prepared in a variety of ways, such as frying, grilling, baking, or steaming. Common types of fish used for fillets include salmon, cod, tilapia, and haddock.