Restaurants may be classified or distinguished in many different ways. The primary factors are usually the food itself (e.g. vegetarian, seafood, steak); the cuisine (e.g. Italian, Chinese, Indian, French, Thai) and/or the style of offering (e.g. tapas bar, a sushi train, a tastet restaurant, a buffet restaurant or a yum cha restaurant). Beyond this, restaurants may differentiate themselves on factors including speed (see fast food), formality, location, cost, service, or novelty themes (such as automated restaurants). Restaurants range from inexpensive and informal lunching or dining places catering to people working nearby, with simple food served in simple settings at low prices, to expensive establishments serving refined food and fine wines in a formal setting. In the former case, customers usually wear casual clothing. In the latter case, depending on culture and local traditions, customers might wear semi-casual, semi-formal or formal wear. Typically, customers sit at tables, their orders are taken by a waiter, who brings the food when it is ready. After eating, the customers then pay the bill. For some time the travelling public has been catered for with ship's messes and railway restaurant cars which are, in effect, travelling restaurants. (Many railways, the world over, also cater for the needs of travellers by providing Railway Refreshment Rooms [a form of restaurant] at railway stations.) In recent times there has been a trend to create a number of travelling restaurants, specifically designed for tourists. These can be found on such diverse places as trams, boats, buses, etc.