Which of these is a territory that is entirely surrounded by the territory of one other state?

An enclave is a territory, or a part of a territory, that is entirely surrounded by the territory of one other state. Territorial waters have the same sovereign attributes as land, and enclaves may therefore exist within territorial waters.

An exclave is a portion of a state or territory geographically separated from the main part by surrounding alien territory (of one or more states). Many exclaves are also enclaves. Enclave is sometimes used improperly to denote a territory that is only partly surrounded by another state. Vatican City and San Marino, enclaved by Italy, Lesotho, enclaved by South Africa, and Nagorno-Karabakh, enclaved by Azerbaijan, are completely enclaved states. Unlike an enclave, an exclave can be surrounded by several states. The Azerbaijani exclave of Nakhchivan is an example of an exclave.

Semi-enclaves and semi-exclaves are areas that, except for possessing an unsurrounded sea border (a coastline contiguous with international waters), would otherwise be enclaves or exclaves. Enclaves and semi-enclaves can exist as independent states (Monaco, Gambia and Brunei are semi-enclaves), while exclaves always constitute just a part of a sovereign state (like the Kaliningrad Oblast).a territory, or a part of a territory, that is entirely surrounded by the territory of one other state