Although both insurance agents and insurance brokers are intermediaries between prospective insurance buyers and insurance providers, the former act more like a broker and the latter act more like an insurance agent.
Clients usually request that their agents to work with a certain specific insurance company. This makes it easier for clients to compare various insurance policies and their quotes and to find the best plan for them, especially when a captive agent works for a large insurance company and is not as familiar with smaller companies and their policies.