The word has also been used by extension to mean any sort of recurring theme, whether in music, literature, or the life of a fictional character or a real person.
Leitmotifs can help to bind a work together into a coherent whole, and also enable the composer to relate a story without the use of words, or to add an extra level to an already present story.
A leitmotif (leitmotiv) is a form of threading device consisting of a melody or sometimes chord sequence that recurs and reminds the audience of a state or some-thing/one with agency (see actor). Originated by Wagner for the range of melodies that cluster round the characters, objects and states in his operas. Transformation in leitmotifs depict transformations in the elements to which they are attached. They are a very powerful structural tool.