Many of the sanctions placed on Iran by the European Union, United Nations and United States were lifted or suspended today:
While a multitude of the sanctions were measures taken to prevent Iran from developing nuclear weapons, others were implemented before 2006 for other reasons. This rolling back of sanctions is because of Iran's compliance with a nuclear deal arranged between itself and the West last year, which was welcomed by the world.
This move allows the Iranian economy to start recovering from years of heavy sanctions. It will benefit the Iranian people while everyone as a whole benefits from continually-improving relations between Iran and the West. In addition, Iran's help is desperately needed to deal with serious issues affecting the Middle East at the moment, so it's in the world's interests to have Iran on board with the international community. The lifting/suspending of sanctions goes a long way towards making that a reality.
The only people who oppose the deal are hardliners and "warmongers" who, for no sane reason, want more conflict in the Middle East. The people in that part of the world are tired of war - they want to fighting to stop, not to escalate.