A more thorough explanation:

Definition: A firm is a title used by one or more people who conduct business together. It refers to the association of people who are united for business purposes. Traditionally, it referred to a partnership, but today it can also refer to a company.

• Law firm: An association of lawyers who practice law together, usually sharing clients and profits. They can be organized as a partnership, professional corporation, or limited-liability company. Many law firms have a hierarchical structure where partners supervise junior lawyers known as associates.
• Captive law firm: A law firm staffed by employees of an insurance company. These lawyers typically defend insureds in lawsuits covered under the insurer's liability policies.

The examples illustrate how a firm can be organized and the different types of firms that exist. A law firm is an example of a traditional partnership where lawyers work together to provide legal services. A captive law firm is an example of a firm that is owned by an insurance company and provides legal services to the company's insured clients.