The International Press as the name suggest is a ‘press’ which you could also call the media group. They cover the entire conference in photographs, videos and take down notes to publish a magazine.
At Model UN, the International Press is a ‘modular’ press which exists at the real UN conferences. MUNs have competitive International Press where you practice your skills to win an award. However, competitions are an overall learning experience where you brush yourself up and not a race where the only intent is to win.