A league or alliance, temporary or permanent and limited in application, such as to conduct the diplomatic and international representation of its constituent regional governments.
In a confederation, the regional governments or states delegate authorities as if to an agent; to a central or national government with the regional governments, as principals, able to take back that authority of its own volition.
The United States began as a confederation in 1777 but a full federation came into being in the final Constitution of the United States of 1787. From 1580 to 1795, the Netherlands formed as a confederation: the United Netherlands.