The prologue actually contains and establishes several poetic and dramatic devices which continue throughout the play.
Poetically speaking, first, the prologue, by itself, is written in the form of a sonnet. It consists of 14 lines written in iambic pentameter, which follow one of the two most common rhyme schemes (ABAB CDCD EFEF GG) for a sonnet. The rest of the play loosely follows iambic pentameter and loosely contains a rhyme scheme.
Also, the prologue includes alliteration ("from forth the fatal loins of these two foes"), idioms ("star-cross'd lovers" and "death-mark'd love"), and metaphor (two hours traffic of our stage). These devices are not only common to "Romeo and Juliet" but all of Shakespeare's works.
Dramatically, the prologue is a picture of the entire play. It contains the setting (Verona) and foreshadowing of the entire plot, including the two main characters from conflicting households falling in love, dying for that love, and resolving their parents' conflict. Finally, the prologue is spoken by a chorus, which is considered a character in Shakespearean plays who often acts like a narrator would, to introduce or sum up the action of a scene.
Iambic Pentameter- each line consists of 10 syllables with the pronunciation patterned as: stressed, unstressed, stressed, unstressed, stressed, unstressed, stressed, and so on...
it has a rhyme scheme of ABABCDCDEFGFGG..
That's as far as I know..