A Local Union is a locally-based group of workers with a charter from a national or international Union such as the International Brotherhood of Electrical Workers (IBEW) or United Auto Workers (UAW). A Local may include workers from the same company or region. It may also have workers from the same business sector, employed by different companies.

Unions work like a democracy. Members of each Local hold elections for officers who bargain and uphold contracts on behalf of the members, giving workers more power on the job. Members vote on their respective contract changes, changes to how their Locals operate (bylaws), and whether they will go on strike. Each member of every Local has a voice within a Union.