What does Jane mean?
The common English feminine of John, from Old French Jehanne, ultimately from Hebrew 'Yochanan' meaning 'Yahweh is gracious.' A John-root grace name, distinct from the Hannah-root names.
What does Joan mean?
A medieval English feminine of John, from Old French Johanne, ultimately from Hebrew 'Yochanan' ('Yahweh is gracious'). Like Jane, it descends from John rather than from Hannah.