The wind horse is an allegory for the human soul in the shamanistic tradition of East Asia and Central Asia. In Tibetan Buddhism, it was included as the pivotal element in the center of the four animals symbolizing the cardinal directions and a symbol of the idea of well-being or good fortune. It has also given the name to a type of prayer flag that has the five animals printed on it.
Depending on the language, the symbol has slightly different names.
In Tibet, a distinction was made between Buddhism (Wylie: lha chos, literally "religion of the gods") and folk religion (Wylie: mi chos, "religion of humans"). Windhorse was predominantly a feature of the folk culture, a "mundane notion of the layman rather than a Buddhist religious ideal," as Tibetan scholar Samten G. Karmay explains.
However, while "the original concept of rlung ta bears no relation to Buddhism," over the centuries it became more common for Buddhist elements to be incorporated. In particular, in the nineteenth century lamas of the Rimé movement, particularly the great scholar Ju Mipham, began to "create a systematic interweaving of native shamanism, oral epic, and Buddhist tantra, alchemical Taoism, Dzogchen, and the strange, vast Kalachakra tantra," and windhorse was increasingly given Buddhist undertones and used in Buddhist contexts.
Windhorse has several meanings in the Tibetan context. As Karmay notes, "the word [windhorse] is still and often mistakenly taken to mean only the actual flag planted on the roof of a house or on a high place near a village. In fact, it is a symbol of the idea of well-being or good fortune. This idea is clear in such expressions as rlung rta dar ba, the 'increase of the windhorse,' when things go well with someone; rlung rta rgud pa, the 'decline of windhorse,' when the opposite happens. The colloquial equivalent for this is lam ’gro, which also means luck."