Young, beautiful creature of ethereal beauty, the princess requires to be strong yet frail, innocent yet cunning, woman and kid at the same time (The neverending story,The princess bride).
She fights for herself and her country, holder of sacred values (Brave).
Her enemy is powerful, evil and equally charming (Snow white and the huntsman).
She loves one person and one only, usually a strong male hero, not always on the right side of the law (Shrek).
In the end she always succeeds and lives happily ever after (Cinderella).