A diplomatic mission is a delegation from a state or supranational organization present in another state to represent the party that sent the delegation. The term usually denotes an embassy, consulate, or other such permanent mission in the capital or major cities of a foreign country.
An embassy is a permanent diplomatic mission, typically placed in the capital of the receiving country. An embassy is run by an ambassador, the foreign nation's highest-ranking representative in the nation receiving the mission. The building which houses an ambassadorial mission is termed a chancery.
A consulate is a mission that deals more with individual people and businesses than an embassy, which primarily deals with governmental matters. A consulate, headed by a consul, is often responsible for the welfare of the nationals of its represented country when abroad. Other typical roles of a consulate are issuing visas, negotiating with businesses, and engaging in public diplomacy. A consulate general is a representative of the embassy in cities other than the capital.
A diplomatic mission does not maintain full extraterritorial status, but remains the territory of the receiving state. However, missions are given protection under the Vienna Convention on Diplomatic Relations, and the receiving state may not enter the chancery without the permission of the nation that operates the embassy.
Quoted from Article III of the Vienna Convention on Diplomatic Relations: "The functions of a diplomatic mission consist, inter alia, in representing the sending State in the receiving State; protecting in the receiving State the interests of the sending State and of its nationals, within the limits permitted by international law; negotiating with the Government of the receiving State; ascertaining by all lawful means conditions and developments in the receiving State, and reporting thereon to the Government of the sending State; promoting friendly relations between the sending State and the receiving State, and developing their economic, cultural and scientific relations."
Diplomatic missions in micronationalism
A number of micronations establish missions in the territory of nations with which they maintain diplomatic relations, often exclusively within nations with which treaties of formal recognition have been signed. Micronations are very rarely capable of creating permanently-constructed chanceries with full staff. As a result, most micronational embassies are small structures that serve a mainly symbolic purpose rather than acting as a de facto seat of discourse between governments. Micronational embassies have been known to be constructed of such materials as Lego bricks or paper cups with flags mounted on toothpicks.
Some micronations conduct diplomacy online through virtual embassies posted on national forums. These embassies serve as a platform for communication between governments in lieu of email, Skype, or other common means.