Sister city relationships (also called twin cities or friendship cities) are formal partnerships between municipalities in different countries, promoting cultural exchange, economic ties, and mutual understanding. Municipalities establish sister city agreements through council resolutions, often based on historical connections, similar industries, cultural links, or educational partnerships. Activities include student exchanges, cultural delegations, trade missions, and sharing of municipal best practices. The federal government through Global Affairs Canada sometimes supports municipal international relationships that advance Canadian interests. Sister city programs face occasional criticism regarding costs and benefits, but supporters value the people-to-people diplomacy and economic development opportunities these relationships can provide.