A wishing well is a term from European folklore to describe wells where it was thought that any spoken wish would be granted. The idea that a wish would be granted came from the notion that water housed deities or had been placed there as a gift from the gods. This practice is thought to have arisen because water is a source of life, and was often a scarce commodity.
Fleetwood Round Table wishing well, The Esplanade, Fleetwood, Lancashire, England
A wishing well in Barrmill, Scotland
A small ornamental garden wishing well, with coins to wish for
A wish is a hope or desire for something. In fiction, wishes can be used as plot devices. In folklore, opportunities for "making a wish" or for wishes to "come true" or "be granted" are themes that are sometimes used.
A fairy offering wishes, illustration by John Bauer to Alfred Smedberg's The seven wishes
Wishes written on red ribbons and tied to a tree in Beihai, Guangxi, China