The Council of the European Union is one of the main institutions of the Community. Together with the European Parliament, it discusses and adopts laws based on proposals from the European Commission.
The Council of the European Union coordinates the policies of the member states, develops the foreign policy and security policy of the Union, concludes agreements on behalf of the EU with other countries or international organisations and jointly with the European Parliament adopts the EU annual budget.
The Council consists of one representative from each member state -at ministerial level-the minister responsible for a given policy area represents his or her country and speaks for it in the Council. The Council meets in different configurations depending on the issues under discussion. The Council has 10 configurations, which cover all policies of the EU.
The presidency of the Council of the European Union works on a rotation basis. Each member state holds the presidency for a period of six months. The exception is the foreign affairs configuration chaired by the High Representative of the Union for Foreign Affairs and Security Policy, Federica Mogherini. To ensure continuity in the work of the Council, the presidency is held by a group of three member-states, known as a trio, for a period of 18 months. The trio prepares and implements a common agenda. Bulgaria is part of the trio Estonia-Bulgaria-Austria and will take over the presidency from Estonia in January 2018.
The Council of the European Union differs from the European Council, which is made up of the heads of state or government of all member states. The European Council defines the general political direction and priorities of the EU and supports the Council of the European Union in developing common policies at high level.
The Treaty of Lisbon introduced the institution of a permanent President of the European Council. The current president is Donald Tusk. His role is to seek consensus between European Council members, facilitates cooperation with the president of the European Commission, report to the European parliament about the activities of the European Council and represent the EU at high level international meetings.
You can find more on the Council of the European Union here.