A prayer wheel is a cylindrical ritual object used by the Vajrayana Buddhists of Tibet. Misinformed Western observers have often claimed that Tibetans believe that turning these cylinders can somehow ‘pray’ for them and hence the English name. This is a misunderstanding.
Ancient Indian monasteries used to have octagonal bookcase which could be turned so as to be able to conveniently reach the books they held. All the books were of course copies of the Buddhist scriptures. The custom developed of walking around these book cases, keeping them to the right, as a way of honouring the Dhamma which the books contained. This custom reached Tibet where it was later modified. Rather than walking around a bookcase, pages from the scriptures were put in small cylinders attached to handles and these were turned manually. Thus the so-called ‘prayer wheel’ is a Tibetan way of respecting the sacred scriptures, equivalent perhaps to placing the Bible or the Quran on a special raised dais or beautifying the edges of their pages with gold leaf.