Insurance Broker
An insurance broker is often an independent intermediary whose job it is to work on your behalf to find the best insurance policy from a range of insurers ( underwriters ). Some intermediaries trade under titles such as 'agent' or 'consultant'. Where this is the case, they might only represent between a handful of insurance companies.
Someone who works directly for one insurance company can only act as an agent for that particular company. Whoever you buy from is obliged to tell you what sort of intermediary they are.