The triquetra is an ancient Indo-European three-pointed symbol representing three-way unity. Sometimes it has a circle running through it and other times it does not. The circle in many belief systems, is a symbol of eternity. The triquetra stands for God the father, Jesus and the Holy Spirit in a Judeo-Christian view (also called the 'Holy Trinity'.) Many Pagans/Wiccans say 'it represents the Triple Goddess as the Maiden, Mother, and Crone'.
A Triquetra is sometimes used as a portal from one plane or time-line to another, such as in the Time Travel spell Chris and Bianca used or when The Charmed Ones used The Power of Three and Dominus Trinus to bridge the gap between the Astral and Earthly (Witch Trial, Chris-Crossed).
- The triquetra is also believed to represent the three planes of existence - Physical, Mental and Spiritual. Notice how, although the three points are clearly separate, they are interlocked together, symbolizing the connection between the three planes--and three sisters.
- The triquetra can also represent the Past, Present, and Future. The tripartite division of the world into the realms of Land, Sea and Sky and the cycle of Life, Death and Rebirth.
- The first person shown on the series, in Something Wicca This Way Comes, a witch named Serena Fredrick, who was murdered by the warlock, Jeremy, had the triquetra tattooed on her body, along with two other victims who Inspector Andy Trudeau believed to be witches, also. Some fans speculate that these witches were somehow tied to and supposed to help, lead or guide the Halliwell sisters in their discovery of their powers.
- A triquetra necklace was given to Charlotte Warren by Neena.
- Latin Tri- "three" and Quetrus- "cornered".
- The triquetra might also be connected to the three Fates (Clotho, Lachesis, and Atropos).