The UN Security Council has fifteen members and decides by nine votes, with a veto for the permanent five

Background

Every sanctions renewal and every mandate extension the Security Council votes on is decided under Article 27 of the United Nations Charter.
The Council has fifteen members in all: five permanent members and ten non-permanent members elected for two-year terms by the General Assembly.
The permanent members are China, France, the Russian Federation (which succeeded the Union of Soviet Socialist Republics), the United Kingdom and the United States.
Each member of the Council has one vote.
Decisions on procedural matters are made by an affirmative vote of nine members.
Decisions on all other matters need an affirmative vote of nine members including the concurring votes of the permanent members — the basis of the right of veto.
If any one permanent member casts a negative vote, the resolution is not approved; a permanent member that does not wish to veto may abstain instead, letting the resolution pass if it still has nine favourable votes.
Under Chapter VI of the Charter, a party to a dispute must abstain from voting on it.