Folklore studies examines orally transmitted narrative, custom and belief, tracing how a legend or practice varies across its tellings and how those variants spread, rather than treating any one version as the authoritative original. The English antiquarian William Thoms, writing under the pen name Ambrose Merton in a letter to the Athenaeum published on 22 August 1846, proposed a good Saxon compound, folk-lore, the lore of the people, to replace the older and clumsier labels popular antiquities and popular literature, and the name he coined gave the emerging field its own identity distinct from literary history.
A folk narrative, a healing charm, a seasonal custom attached to a religious festival, rarely survives in one fixed form, and folklore studies is built to compare its documented variants rather than to adjudicate which version is true. The atlas relies on the discipline wherever a popular religious practice or legend, a saint's local miracle story, a folk remedy tied to a festival, needs its documented variants and transmission history set out rather than a single telling repeated as though it were the only one that ever existed. Thoms himself drew the term from earlier folklorists' scattered county collections, and coining a single word for the subject is what let those collections be recognized as one field of study rather than a shelf of unrelated local curiosities.