Fish are consumed as food by many species, including humans. It has been an important source of protein and other nutrients for humans throughout recorded history.
In culinary and fishery contexts, the term fish can also include shellfish, such as molluscs, crustaceans and echinoderms. English does not distinguish between fish as an animal and the food prepared from it, as it does with pig vs. pork or cow vs. beef. Some other languages do, as in the Spanish versus . The modern English word for fish comes from the Old English word fisc (plural: fiscas) which was pronounced as it is today. English also has the term seafood, which covers fish found in the seas and oceans as well as other marine life used as food.
Over 32,000 species of fish have been described, making them the most diverse group of vertebrates. In addition, there are many species of shellfish. However, only a small number of species are commonly eaten by humans.
Fish can be prepared in a variety of ways. It can be uncooked (raw) (e.g., sashimi). It can be cured by marinating (e.g., ceviche), pickling (e.g., pickled herring), or smoking (e.g., smoked salmon). Or it can be cooked by baking, frying (e.g., fish and chips), grilling, poaching (e.g., court-bouillon), or steaming. Many of the preservation techniques used in different cultures have since become unnecessary but are still performed for their resulting taste and texture when consumed.