In lang=en terms the difference between invoke and herald
is that
invoke is to solicit, petition for, appeal to a favorable attitude while
herald is to proclaim or announce an event.
As verbs the difference between invoke and herald
is that
invoke is to call upon (a person, especially a god) for help, assistance or guidance while
herald is to proclaim or announce an event.
As a noun herald is
a messenger, especially one bringing important news.