FBS is an A-Book NDD (no-dealing desk), non-market-maker brokerage company, which provides STP and ECN accounts.
What does it mean?
As an A-Book broker, FBS directs clients' trade orders right to liquidity providers. In turn, B-book brokers keep their clients' orders internally. They take the other side of their clients' trades, which means that the brokers' profits are often equal to their clients' losses.
Compared to B-book brokers, there is no conflict of interest between clients and A-book brokers since the earnings of A-book companies are not equal to the losses of their clients. This makes A-book brokers more trustworthy.