The talk of diplomacy is all over the news, and can take over political coverage during election cycles and times of foreign relations crises. Instinctively, we know what diplomacy is, even though it's somewhat hard to pin down exactly.
In short, it's about maintaining relationships with other nations. It is conducted by governments in general, but overseen and facilitated by diplomats. We've all heard of diplomatic immunity, but who exactly is a diplomat?
There are four levels of diplomats, and the rank and duties of each were determined by the 1961 Vienna Convention on Diplomatic Relations. Except for minor differences in terminology, the duties and roles of each rank are pretty consistent throughout all major participating governments.
The overall duty of any diplomat is to establish relationships in the host country, that enables open communication and trust between the home country and the host - although it doesn't always work out that way, and some diplomatic relationships are little more than cover for intelligence gathering on both sides.
There is no specific training that is required to be a diplomat, but most individuals have degrees in law, international business, political science or economics. The most important factor, however, is relationships.
An ambassador is the top diplomat, the one who runs the embassy. The purpose of the job is to provide protection for citizens of the home country who are visiting the host country, and to work toward peaceful negotiation and increased trade between the home and host country.
In the days before the world was so well connected by transportation and communication, ambassadors were very powerful and operated almost autonomously as representatives of their heads of state. It was not uncommon for the U.S.'s early presidents to communicate with their foreign ambassadors once or twice per term.
Today, the world has 'shrunk' via instant communication and rapid transit. This allows heads of states to frequently check-in with their ambassadors and direct their activities - the modern ambassador has greatly reduced power, and is generally the face of the home country's foreign relations.
An envoy is the second-highest ranking diplomat, and unlike the ambassador, is not officially a representative of the home country. The envoy does, however, have the authority to carry out the home country's business in the host country, and is granted many of the same privileges as the ambassador.
In situations where there is openly-acknowledged intelligence-gathering happening from within the embassy, the people assigned to that role may be given the envoy title.
If the espionage is discovered, the envoy can be sent home - but host countries in which this type of relationship is typical are generally aware of espionage operations and prefer to keep the envoy close by. That said, most envoys are just regular diplomats, not spies - but if there's a so-called non-secret spy, it's usually an envoy.
A minister technically ranks below the envoy, but answers directly to the ambassador. They are generally heads of particular diplomatic missions, and may represent the ambassador in areas or at functions where sending a higher-ranking individual is unwarranted or unwise.
Oddly, although the minister ranks above the chargé d'affaires, the charge is actually the lead on many projects in which the minister takes part. Confused yet?
The chargé d'affaires is the lowest-ranked diplomatic position, yet functions as a replacement for the ambassador when the ambassador is unable or unwilling to lead a mission.
The chargé d'affaires is in the difficult position of being in charge of the higher-ranked minister and envoy, and takes the lead on certain missions. The charge may function as an interim head of a mission, paving the way for higher-ranking diplomats to enter a new host country, or may be in charge of special diplomatic projects within the embassy.