The United Nations is an international organization founded in 1945. It is currently made up of 193 Member States. The mission and work of the United Nations are guided by the purposes and principles contained in its founding Charter.

Due to the powers vested in its Charter and its unique international character, the United Nations can take action on the issues confronting humanity in the 21st century, such as peace and security, climate change, sustainable development, human rights, disarmament, terrorism, humanitarian and health emergencies, gender equality, governance, food production, and more.

The UN also provides a forum for its members to express their views in the General Assembly, the Security Council, the Economic and Social Council, and other bodies and committees. By enabling dialogue between its members, and by hosting negotiations, the Organization has become a mechanism for governments to find areas of agreement and solve problems together.

The UN's Chief Administrative Officer is the Secretary-General.

The UN Secretariat comprises the Secretary-General and tens of thousands of international UN staff members who carry out the day-to-day work of the UN as mandated by the General Assembly and the Organization's other principal organs.  The Secretary-General is chief administrative officer of the Organization, appointed by the General Assembly on the recommendation of the Security Council for a five-year, renewable term. UN staff members are recruited internationally and locally, and work in duty stations and on peacekeeping missions all around the world.  But serving the cause of peace in a violent world is a dangerous occupation. Since the founding of the United Nations, hundreds of brave men and women have given their lives in its service.

The UN system, also known unofficially as the "UN family", is made up of the UN itself and many affiliated programmes, funds, and specialized agencies, all with their own membership, leadership, and budget.  The programmes and funds are financed through voluntary rather than assessed contributions. The Specialized Agencies are independent international organizations funded by both voluntary and assessed contributions.