The Security Council is the UN's most powerful body, and it has the responsibility of maintaining international peace and security. The SC is made up of five countries that serve as Permanent Members and ten Elected Members with terms of two years. This body carries out military operations, imposes sanctions, control arms inspections, deploys election monitors and more. It is responsible for acting to resolve international conflicts or crises.
Each of the fifteen Members has one vote. Even though all of the United Nations’ Member States are not part of the SC at the same time, they are all obligated to follow the Council decisions and mandates. Additionally, the five Permanent Members hold the "veto power," which is a right they obtained when they set up the UN in 1945 (after winning WWII). These countries holding the "veto power" are the Unites States of America, the United Kingdom of Great Britain and Northern Ireland, the Republic of France and the Russian Federation.
The Security Council basically determines the existence or not of a threat to peace. It also calls upon parties to a dispute or conflict to settle it by peaceful means and suggests and/or recommends methods to a fair settlement.
This body recommends the General Assembly the appointment of the Secretary General and the admission of new Members to the organization. Along with the GA, it elects the judges of the International Court of Justice (ICJ).