Labour law (also labor law or employment law, see spelling differences) mediates the relationship between workers (employees), employers, trade unions and the government. Collective labour law relates to the tripartite relationship between employee, employer and union. Individual labour law concerns employees rights at work and through the contract for work. Employment standards are social norms (in some cases also technical standards) for the minimum socially acceptable conditions under which employees or contractors are allowed to work. Government agencies (such as the former US Employment Standards Administration) enforce labour law (legislative, regulatory, or judicial).