In Spain, it is possible to find fresh anchovies, usually in Andalusia, fried in batter, but elswhere it is normally the preserved fillets. The nomenclature does vary from place to place, but generally speaking anchoas are the salt-cured brown fillets and boquerones, the white ones marinated in vinegar.
Anchoas are found on cocktail sticks as a component of a gilda, as part of a salad or dissolved in a sauce to add a salty richness. Boquerones may have olive oil mixed with the vinegar which is seasoned with garlic and herbs and are normally served as a tapa. An interesting variation is the matrimonio, which combines the two.