More on Principal Organs of the United Nations from Infoplease:

• The United Nations - The United Nations In 1945, the United Nations was founded by "peace-loving states" ...
• United Nations Security Council - The Security Council was constructed as an organ with primary responsibility for preserving peace. Unlike the General Assembly, it was given power to enforce measures and was organized as a compact executive organ. Also unlike the assembly, the Security Council in theory functions continuously at the seat of the United Nations.
• United Nations: meaning and definitions - United Nations: Definition and Pronunciation
• United Nations - United Nations Preamble of the United Nations Charter The Charter of the United Nations was adopted ...
• United Nations Organization: meaning and definitions - United Nations Organization: Definition and Pronunciation