The International Association of Athletics Federations (IAAF) is a big group of people who help organize and make rules for running, jumping, throwing, and other kinds of athletic events all around the world. They work together to make sure athletes can compete fairly and safely, and to help organize big events like the Olympics or World Championships. It's kind of like having a bunch of grown-ups in charge of making sure everyone plays by the rules when you're playing a game with your friends!