Hell's Kitchen is a cooking school actually. They take people with some culinary background and try to put them into situations where they run different stations in a kitchen and even run the kitchen. For instance, they will have people who have never cooked on a line before. Putting that person in a situation where they are expected to keep up with that is setting them up for failure...and a lot of Gordon Ramsay screaming.

Top Chef gets people who have some accolades and get them to compete against one another.