Brine is water saturated or nearly saturated with salt. It is used (now less popular than historically) to preserve vegetables, fish, and meat. Although brine is used in preservation much like sugar or vinegar, it can be used to great effect in transportation. Brine is a common fluid used in the transport of heat from place to place. It is used because the addition of salt to water reduces the freezing temperature of the solution and a relatively great efficiency in the transport can be obtained for the low cost of the material. Brine is also commonly used to age Feta Cheese.