A boning knife has an extremely narrow and flexible blade that tapers to a pointed tip. It’s used to debone cuts of meat more efficiently and reduce waste in the process. It can cut through those tough connective tissues and joints that other knives struggle with. Just remember, cut around bones, not through them. It can also be used to remove the skin from fish as it helps to easily separate the flesh.
Fillet knives are specifically designed for cutting fish and removing bones. A wide array of fish knives with various cutting edges exists - but the most common ones are fillet knives, large serrated knives and those designed for cutting tuna.