A sister city has a long-term relationship and partnership with another city. These relationships usually form with the purpose of cultural exchange. Sister cities are officially approved by the legislature of each city, which permanently links the two jurisdictions.
Sister cities can be formed in multiple ways. Sometimes it happens when two mayors meet and become friends, deciding to extend that mutual friendship to their respective cities. Other cities decide to link because they share the same name or celebrate similar festivals. Once two cities are linked, they share a broad relationship that facilitates the close exchange of ideas and cultures.