An alliance is an agreement by two or more parties to work together towards a common goal. For example, the United States formed an alliance with Great Britain and France during World War I.
The Iroquois Confederacy consist of 5 different Native American tribes from New York. These tribes include the Onondaga, Seneca, Cayuga, Oneida, and Mohawk. This confederacy had a well organized political structure and formed an alliance with each other as a means of protection against other tribes/countries.