A more thorough explanation:

A shop committee is a group within a union shop that helps resolve employee complaints. A union shop is a workplace where employees are represented by a labor union. The shop committee is responsible for addressing any issues that arise within the union shop.

For example, if an employee has a problem with their working conditions or pay, they can bring it to the attention of the shop committee. The committee will then work with the employer to find a solution that is fair to both parties.

Other types of shops include:

• Agency shop: A union acts as an agent for the employees, regardless of their union membership. Non-union members must pay union dues because it is presumed that any collective bargaining will benefit non-union as well as union members.
• Closed non-union shop: An employer restricts employment to workers who are unaffiliated with any labor union.
• Closed shop: An employer, by agreement with a union, hires and retains in employment only union members in good standing. Closed shops were made illegal under the federal Labor–Management Relations Act.
• Open closed shop: An employer hires non-union workers on the understanding that they will become union members within a specified period.
• Open shop: A shop in which the employer hires workers without regard to union affiliation.
• Preferential non-union shop: Non-union members are given preference over main members in employment matters.
• Preferential union shop: Union members are given preference over non-union members in employment matters.
• Union shop: The employer may hire non-union employees on the condition that they join a union within a specified time (usually at least 30 days).

These different types of shops illustrate the various ways in which unions and employers can work together to represent employees. Each type has its own rules and regulations, and it is important for employees to understand their rights and responsibilities within their workplace.