Limes are citrus fruits which are typically round and green. There are many species of citrus trees with fruits referred to as 'limes', like the Key lime, Persian lime (being the most common), Kaffir lime and Desert lime. Limes are sour and rich in vitamin c
Limes have high contents of sugars and acids, but some varieties lack in citric acid (ref). It is used in cooking for its juices and zest, the juice can be concentrated, dried, frozen or canned.