Diplomacy is about relations between countries. For example countries can make an agreement together, such as a treaty. Diplomacy is the talk between the representatives of states, such as their heads of state. Sometimes, these talks are about trade or business, and sometimes they are about war and peace. Diplomacy happens a lot when two or more countries fight.
Diplomacy can be an action, a skill, or a job. The skill of diplomacy uses tact, like choosing words that are friendly and polite when writing to other countries. People doing diplomacy as a job find solutions to a common problem between countries, or put their country in a better strategic position among other countries.
The people doing the job of diplomacy are called diplomats. They are sent from their home country, to meet with and talk to diplomats and leaders of foreign countries. An important type of diplomat is called an ambassador. An ambassador lives in a foreign country and works in an embassy to be available for meetings with the government of that country.