The term "Elfstones" refers to magical artifacts in the fantasy series created by Terry Brooks, particularly in the novel "The Elfstones of Shannara." These stones are imbued with powerful magic and are used by the Druids to protect the realm of Shannara from various threats. In the story, the Elfstones are sought after for their ability to enhance the abilities of their wielder and to combat dark forces. The narrative explores themes of heroism, sacrifice, and the struggle between good and evil, as characters embark on quests to harness the power of the Elfstones for the greater good.