The concept of a triple goddess appears in many cultures, religions, and mythologies. Essentially, she is a goddess with three aspects, or in some cases she may be represented by three separate individuals who are linked together and often appear together. There are a number of forms of the the triple goddess, and a number of ways to interpret her, and some people argue over the precise nature of this goddess in various religions.
Triple goddesses appear to be ancient, appearing in various forms in a number of religions. For example, many Greek goddesses were actually worshiped as triple goddesses, with a complex multitude of aspects. The Romans had these goddesses as well: Diana, for example, was the goddess of the hunt, goddess of the moon, and goddess of the Underworld.
In addition to appearing in the form of a goddess, a mythological figure with a tripled aspect can also be a lesser being. The Three Fates of Greek mythology, for example, are a form of the triple goddess, as are the Three Graces. The concept of a single sacred being with many facets also appears in the form of the Christian Trinity of Father, Son, and Holy Ghost.
Worship of the triple goddess may be so common in world religions because it allows religious followers to appreciate the multiple facets of a single personality or individual. The goddess symbolizes the complexity of women, and the fact that people are rarely as simplistic as to have only one side. The commonality of the number three in particular, rather than any other number, may be related to the fact that three is a number with powerful religious and cultural symbolism for many cultures.
Many good and evil figures in mythology appear in triads, and the number three pops up in other ways as well. For example, Cerberus, guardian of the underworld, is often depicted with three heads, and according to legend, the Buddha studied through a threefold training on the way to enlightenment.
In Neopaganism, the triple goddess appears in the form of three aspects of womanhood, representing the maiden, the mother, and the crone. The maiden represents young women, full of potential and life, while the mother symbolizes a fully mature woman. The crone symbolizes elderly women and the wisdom which comes with aging.