What is the difference between the 'The Trolley Problem and 'the fat man problem' ?

The trolley problem is part of almost every introductory course on ethics, and it's about a vehicle killing people. ... As the trolley driver, you are not responsible for the failure of the brakes or the presence of the workers on the track, so doing nothing means the unintentional death of five people. No Solution, No Problem

Like most philosophical problems, the Trolley Problem is not designed to have a solution. It is, rather, intended to provoke thought, and create an intellectual discourse in which the difficulty of resolving moral dilemmas is appreciated, and our limitations as moral agents are recognized. The trolley problem is a question of human morality, and an example of a philosophical view called consequentialism. This view says that morality is defined by the consequences of an action, and that the consequences are all that matter. The trolley problem is a series of thought experiments in ethics and psychology, involving stylized ethical dilemmas of whether to sacrifice one person to save a larger number. ... If you pull this lever, the trolley will switch to a different set of tracks. However, you notice that there is one person on the side track.