A relish is a cooked or pickled, chopped vegetable or fruit food item which is typically used as a condiment. The item generally consists of discernible vegetable or fruit pieces in a sauce, although the sauce is subordinate in character to the vegetable or fruit pieces. It might consist of a single type of vegetable or fruit, or a combination of these. These fruits or vegetables might be coarsely or finely chopped, but generally a relish is not as smooth as a sauce-type condiment, such as ketchup. The overall taste sensation might be sweet or savory, hot or mild, but it is always a strong flavor that complements or adds to the primary food item that it is served with.
Relish probably came about from the need to preserve vegetables in the winter.
Although chutneys might be considered a type of relish, Crosse & Blackwell defines the difference between chutneys and relishes as follows: "Chutney is typically made with fruit; relish is normally made with vegetables."
In the United States, the most common commercially available relishes are made from pickled cucumbers and are known in the food trade as pickle relishes. Two variants of this are hamburger relish (pickle relish in a ketchup base or sauce) and hotdog relish (pickle relish in a mustard base or sauce). Other readily available commercial relishes in the United States include corn (maize) relish. Heinz, Vlasic, and Claussen are well known in the United States as producers of pickles and relishes.
A famous relish is the Gentleman's Relish, which was invented in 1828 by John Osborn and contains spiced anchovy. It is traditionally spread sparingly atop unsalted butter on thin, hot toast.