A darne is a thick slice or steak cut across the backbone of a round fish. It includes the bone. It is sometimes called a ‘steak’. A darne is a thick, cross-section cut from a round fish,  perpendicular to the spine. Steaks often retain part of the  backbone.

A délice is a folded fish fillet. Usually both ends of the fillet are folded in so there are three layers. Sometimes the thin end is threaded through the thick end. It is sometimes stuffed.

A fish fillet, from the French word filet (pronounced [filɛ]) meaning a thread or strip,[1] is the flesh of a fish which has been cut or sliced away from the bone by cutting lengthwise along one side of the fish parallel to the backbone. 

Goujons are fish fillets cut into finger sized strips, on the diagonal of the fillet. They are often crumbed and fried. 

A small round piece of fish cut from a fillet.

A suprême is a steak cut on the diagonal from a large fillet. Traditionally, the skin is removed. It is generally poached and served with a sauce.