The Star and Diamonds classification is based on a certification by an independent board. It considers, on the one side, the quality of a hotel (basically the room), which is rated with stars, and on the other side, the quality of its service and staff, to be rated diamonds. This classification will be renewed every year.
Five-diamond hotels meet the highest requirements for rating: the beds are comfortable, bathrooms are in excellent working order, all facilities are renovated regularly, infrastructure is top-tier, and service and hygiene meet the highest international standards. Five-star hotels usually offer similar quality, but with lower levels of service and detail in the rooms. For example, a five star hotel may have less luxurious linens, or perhaps room service during limited hours rather than 24 hours.
Four-star hotels are less expensive and more basic, but they still guarantee cleanliness and basic service such as hot water and purified drinking water. Three-, two- and one-star hotels are at least working to adhere to certain standards: bathrooms are cleaned and linen is washed daily, and you can expect a minimum standard of service. Two- and one-star hotels generally provide bottled water rather than purified water.