Culture is the key concept of the field of ethnology. In this book, it is defined as the shared, socially learned knowledge and behavioural patterns characteristic of some group of people. It is useful to distinguish between its mental and behavioural components, or between cultural knowledge and patterns of behaviour. Cultural ideas and beliefs serve as more than just rules or instructions for behaviour.Cultural knowledge limits and influences behaviour but does not determine it in great details for peoples' behaviour is not simply programmed by their culture.