Though some Wiccans believe in just a Goddess, many believe in the dually balanced male and female deities.
After this main guideline, the beliefs differ in extreme ways. Some Wiccans have chosen specific Gods and Goddesses from different cultures or time periods, and some are happy without specific names or titles. The most popular 'Wiccan' Goddess and God aspects are listed below, but feel free to search further for specific Gods and Goddesses from Roman, to Greek, to Egyptian, etc.
The triple goddess means one Goddess with three aspects that correspond with the phases of the moon. The waxing, full, and waning moons. The three aspects are the Maiden, the Mother, and the Crone. The new moon is not accounted for however. Some merge the Crone, or waning moon, in with the New Moon, and some believe there is a fourth dark and unseen Goddess. Again, these beliefs differ for every Wiccan.
Maiden: Represents the Waxing Moon phase. She stands for childhood, adolescence, beginnings, purity, virginity, independance, and courage.
Mother: Represents the Full Moon phase. She stands for motherhood, protection, fertility, growth, and sexuality.
Crone: Represents the Waning Moon phase. She stands for old age, wisdom, change, transformation, death, rebirth, and banishing.
The God aspect of Wicca is known as the Horned God. Like the Goddess with her three personas, the God has two main figures. The first is the Sun-God which coincides with the sabbats and seasons, much like the tripple goddess with the lunar changes.
The story of the Sun God begins on Yule when he is reborn every year, bringing the beginning reign of light again.
At Imbolc he continues to grow with the days, growing longer in length. He begins coming into his full youth while the Goddess is too in her Maiden aspect.
Together they grow until Ostara. The God is now a young man and takes the Goddess as his bride.
On Beltane their marriage is consumated with a joyous celebration.
On Litha the Sun God reaches his peak of life with the Summer Solstice. The Goddess is now in her Mother aspect.
On Lammas he dies, remembering that through all death is life.
On Mabon, he is mourned by the Goddess, now heading into her Crone stage. He resides in her womb, awaiting Summerland.
At Samnhain he returns to Summerland and awaits rebirth. There he waits, growing younger until he is reborn again at Yule. The Goddess is now fully in her Crone form.
The second persona of the Horned God lies with the two dual personalities that represent summer and winter, light and dark. The 'Twins' battle twice, on the two Solstices.
The Oak King reigns from Midwinter to Midsummer. Like the Oak tree, strong and dominant, he represents light, growth, strength, and longevity.
The Holly King defeats his light twin on Litha, leading the days back into darkness. Like the dark season, he represents rest and patience. The holly tree is somewhat of a sign of hope during the cold winter, much like the Holly King. The green leaves, and red glowing berries stand against the dead fruitless trees. On Yule again, the Oak King takes his reign.