It is the largest international organization.
All countries in the world are the members in UN.
The aim of UN to ensure international peace, security and respect for human rights.
UN has group of organizations that work on the specific themes.
UN organisations include: World Food Programme, Food and Agricultural organization (FAO), the World Health Organization (WHO) and United Nations Conference on Trade and Development (UNCTAD).
World Trade Organization (WTO) is not part of UN but it works with UN.