The General Assembly is one of the main six organs of the United Nations, the main deliberative, policymaking and representative organ. Members of the GA meet once a year and approve United Nations budget. They discuss international issues such as peace and security, development, international law, etc.
The Security Council has primary responsibility for the maintenance of international peace and security. It is made of fifteen members, five of whom are permanent and ten are elected, non-permanent members. They are elected by the General Assembly every two years. A decision can be vetoed by any one of its permanent members.