What is the difference between a closed shop and lockout?

A closed shop is a union security agreement where an employer agrees to hire only union members, ensuring that all employees are part of the union. In contrast, a lockout is a temporary work stoppage initiated by the employer during a labor dispute, preventing employees from working until an agreement is reached. Essentially, a closed shop restricts hiring to union members, while a lockout is a tactic used by employers to exert pressure during negotiations.