Hotel ratings are issued by the government in most European countries (except Switzerland where it's done by voluntary organizations). In the United States, it's provided reliably by AAA and Michelin. The stars are provided based on the amenities provided by the hotel.

The five categories/grades are:
5 star (Luxury): Located in major cities. Elegant décor, plush lobby, first class service and accommodation, valet parking, concierge service, room service, well-equipped fitness centers and state-of-the-art business centers, the amenities included below are also a must.

4 star (Deluxe/upscale hotels): Prime location, comfort, class and quality service. Tasteful décor, valet parking, concierge service, fitness and business centers.

3 star (Mid-scale hotels): Amenities of swimming pool, fitness center, room service, concierge service and parking.

2 star (Value properties): Affordably priced, well decorated rooms but not elegant, no restaurant or room service available, sometimes there may be a swimming pool.

1 star (Economy hotels and motels): Simple accommodation, cable television, local calls and free parking. Some motels provide swimming pools as well.