Tens of millions of workers around the world are affiliated, through their union membership, to one of the global union federations (GUFs). These international unions cover every industry, from transport to finance to public services. They work to support their affiliates throughout the world, providing support during industrial disputes, training union members, and bringing pressure to bear on multinationals and governments. This book serves as a short introduction to the GUFs, as well as the International Trade Union Confederation, and a starting point for union members who want to learn more about the international dimension of our movement.