Gastronomy is a compound word that derives from the ancient Greek words γαστήρ -τρός "stomach" and -νομία "-rule". It is the study of the relationship between food and culture, the art of preparing and serving rich or delicate and appetizing food, the cooking styles of particular regions, and the science of good eating. One who is well versed in gastronomy is called a gastronome, while a gastronomist is one who unites theory and practice in the study of gastronomy. Practical gastronomy is associated with the practice and study of the preparation, production, and service of the various foods and beverages, from countries around the world. Theoretical gastronomy supports practical gastronomy. It is related with a system and process approach, focused on recipes, techniques and cookery books. Food gastronomy is connected with food and beverages and their genesis. Technical gastronomy underpins practical gastronomy, introducing a rigorous approach to evaluation of gastronomic topics.