These are images that possess various magic powers and are used for various purposes. Many spirits possess a specific image (a seal or sigil) that transmits its essence and may be used to summon or theoretically control them. Sigils and seals are usually geometric but may be representational. They are integral to medieval methods of commanding and compelling spirits.
The word sigil derives directly from the Latin sigilum, meaning “seal” (hence sigil and seal are used synonymously). Many sigils incorporate Hebrew letters and words and may or may not derive from Kabbalistic traditions and ancient Jewish magic. (Medieval Christian demonologists also commonly incorporated Hebrew into sigils.) The word sigil may also relate to the Hebrew word segulah, which has various, complex meanings. A segulah may be a talisman, treasure, virtue, remedy, or something possessing the power to heal or effect spiritual change.
The most famous sigil is the Seal of Solomon, also commonly called a Jewish star, which is a hexagram, two interlocking triangles, representing the perfect union of the male and female principles.