The Advisory, Conciliation and Arbitration Service (Acas) is a non-departmental public body of the Government of the United Kingdom. Its purpose is to improve organisations and working life through the promotion and facilitation of strong industrial relations practice. Acas provides employment law and employment relations advice for employers and employees through its website and helpline. It also offers dispute resolution services such as arbitration or mediation, although the service is perhaps best known for its collective conciliation function – that is resolving disputes between groups of employees or workers, often represented by a trade union, and their employers.