How is diplomacy different than discussion?

The main difference between diplomacy and discussion is intent.

Discussion is a broad term meaning to talk and exchange information. Two business people can talk about the rise of the stock market, giving their opinions and personal or business information related to the companies they are interested in, have investments with or think are good short or long term investments. The intent is just to talk or have a discussion, nothing that would necessarily directly benefit either of the two business people.

Diplomacy can be considered a form of discussion in that it involves talking and exchanging information, but the intent of diplomacy is to arrange a situation which is beneficial to one or more parties and includes negotiating in order to achieve it. Now let's examine the businessmen again, this time they are heads of large international organizations. The one represents a country who is open to having foreign investment to give jobs to people of their country and also through operating would give money to the government. The other business person represents a large company that is looking for a country that would allow it to do business for the lowest possible costs. The business people both need diplomacy to get what the want, the one want money for the people and government, the other wants to make the most money for the company. In order to reach a balance, they will need diplomacy which includes negotiating and perhaps settling for something that is not perfect for each, but benefits both in some way.