A cook can be a member of a household staff who prepares food and manages the kitchen staff. Often, big households employ a cook-housekeeper. A chef, on the other hand, is likely to be heading a team of cooks in a restaurant or hotel. A cook is considered an inferior title than that of a chef. Domestic staff in modern households are generally expected to be good cooks also. They may do all kinds of other household duties apart from cooking for the members of the family they work for.
A chef, on the other hand, even if employed in a large household, normally would stick to cooking alone. A chef is also more of a technical title and is further listed according to specializations like in any other profession. Therefore, you can have a Chef de Cuisine who is in charge of the functioning of the kitchen and its functioning. He may or may not cook but simply manage the team in the kitchen. Sous Chef who is in charge specifically of the cooking and supervision of the staff. Both these titles define mainly supervision-related duties. Chef de Partie are the people who specifically get down to the nuts and bolts of cooking. Among cooks who work as junior staff in a hotel or restaurant kitchen, the classifications can be as follows: A Sauté cook takes care of all sautéed dishes and sauces and cooks fish if there is no specialist fish cook around. A Roast Cook is responsible for broiling, grilling and baking while a Vegetable cook, as the name suggests, takes care of soups and vegetable dishes