The audience knows that the masked young man is romeo entering the capulets ball is romeo a montague but the characters do not this creates

Dramatic Irony

Explanation:

Dramatic irony is demonstrated as the literary devices in which the audiences' are aware of a specific situation, cause of conflict, or its resolution but the characters are not. It helps the author in developing tension among the readers and building suspense as the readers' are uncertain about the characters' next move. Similarly, in the given example audience knowing about the 'masked young man being Romeo, a Montague' and characters not having an idea of this exemplifies 'dramatic irony.'

about the letter or who wrote the letter

i think its a waste but, it also important for are education