The United Nations is an organization. It is an organization made up of all of the countries in the world. Each country is represented in the United Nations and is able to vote on a variety of issues. Because it is an organization, there cannot really be an example of the United Nations. There can be examples of things the UN does, but there cannot really be an example of the UN itself.
The UN does many things. It sends soldiers to various countries in the world where conflict is going on. When it does this, the mission of the soldiers is to keep the opposing sides apart. These soldiers are called peacekeepers. This is an example of the sort of thing that the UN does.
The main implication of the UN is that it gives the countries of the world a way to try to solve problems without having to resort to violence. The UN gives them a chance to have diplomatic contacts with one another instead of simply fighting. This is an important way of trying to keep the peace in the world.