Star ratings are given by the AA, English Tourism Council and the RAC, and they basically mean that these hotels have been visited and accredited.
Hotels are given a rating from 1 - 5, the more stars the higher the quality and the greater the range of facilities and level of service provided.
Diamond ratings are given to the rest of the wide variety of accommodation including guesthouses, bed and breakfasts, inns and farmhouses. Again, diamonds are rated from 1 - 5, with 5 being the highest. Diamond ratings reflect visitors' expectations, and quality is seen as more important than facilities.