A dryad is a tree nymph or tree spirit in Greek mythology. Drys (δρῦς) signifies "oak" in Greek. Dryads were originally considered the nymphs of oak trees specifically, but the term has evolved towards tree nymphs in general. Often their life force was connected to the tree in which they resided and they were usually found in sacred groves of the gods. They were considered to be very shy creatures except around the goddess Artemis, who was known to be a friend to most nymphs.

A nymph is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature, are typically tied to a specific place or landform, and are usually depicted as maidens. They were immortal like other goddesses, except for the Hamadryads, whose lives were bound to a specific tree.