The unit of labour organization which organizes and charters locals in the industries or trades as defined in its constitution, sets general policy for its locals, assists them in the conduct of their affairs, and is the medium for co-ordinating their activities. Finances are obtained from the locals through per capita dues. Unions usually hold regular conventions of delegates from the locals at which general policy is set and at which officers are elected. A union may be affiliated with a larger labour organization (e.g.. congress, federation. labour council).