Final answer:
A labor union is an organization of workers that negotiates with employers over wages and working conditions. It seeks to change the balance of power between employers and workers by requiring employers to deal with workers collectively. This process is known as collective bargaining.
Step-by-step explanation:
A labor union is an organization of workers that negotiates with employers over wages and working conditions. A labor union seeks to change the balance of power between employers and workers by requiring employers to deal with workers collectively, rather than as individuals. As such, a labor union operates like a monopoly in a labor market. We sometimes call negotiations between unions and firms collective bargaining.