Jersey (, ; Jèrriais: "Jèrri" ), officially the Bailiwick of Jersey (; Jèrriais: "Bailliage dé Jèrri"), is a Crown dependency of The Crown located near the coast of Normandy, France. Jersey was part of the Duchy of Normandy, whose dukes went on to become kings of England from 1066. After Normandy was lost by the kings of England in the 13th century, and the ducal title surrendered to France, Jersey and the other Channel Islands remained attached to the English crown. 

The bailiwick consists of the island of Jersey, the largest of the Channel Islands, along with surrounding uninhabited islands and rocks collectively named Les Dirouilles, Les Écréhous, Les Minquiers, Les Pierres de Lecq, and other reefs. Although the bailiwicks of Jersey and Guernsey are often referred to collectively as the Channel Islands, the "Channel Islands" are not a constitutional or political unit. Jersey has a separate relationship to the Crown from the other Crown dependencies of Guernsey and the Isle of Man, although all are held by the monarch of the United Kingdom. 

Jersey is a self-governing parliamentary democracy under a constitutional monarchy, with its own financial, legal and judicial systems, and the power of self-determination. The Lieutenant Governor on the island is the personal representative of the Queen.
Is this a political unit?
 the "Channel Islands" are not a constitutional or political unit