What is the veto power of the Security Council?

All decisions taken by the United Nations are on matters
classified as either procedural or substantive. Each of them has to be ratified by the
Security council.

The United Nation's Security council
consists of 15 members nations. Five of them have a permanent membership and they
include the US, the UK, China, France and the Russian Federation. The other members of
the Security council are non-permanent and are elected for a term of two years by the
members of the General Council.

Draft resolutions
pertaining to procedural matters only need 9  affirmative votes by any of the 15 members
of the security council to be passed. Those involving substantive matters on the other
hand require 9 affirmative votes by any of the 15 member nations, as well as no negative
vote by any of the five permanent members. If any of the permanent members casts a
negative vote, the draft resolution being ratified cannot be accepted.
This special privilege given to the five permanent members is called the
veto power. It ensures any decision taken on substantive matters has the
approval of all the permanent members.