Financial Intermediaries have existed as long as money in one form or another.
They currently exist in 2 forms independent and tied. Both hold the same qualifications i.e. the same levels of knowledge and skill etc.
The biggest adavantage of independents being they work for you and not for anyone else.
The general process of the job they do is 2 fold they either do a financial review for you and guide you on matters such as savings and investments, protection, mortgages, pensions, tax etc they offer you proffessional advice to ensure you get the correct product for you and in the case of independents that you get the best deal available from which ever provider offers whatever you need.
Or you say to them I need a mortgage / pension etc and they explain to you how mortgages or whatever work they talk you through what is available to you you say i like that type and then they get you the best deal available. And ignore the rest of your financial situation if that is whats preffered.
Hope that helps