If you want to know just about the line you quote, "But soft! What light through yonder window breaks?" Romeo is personifying the light and giving it the power to break through the window. This light is actually the candle light and you are to assume it is the light that is also illuminating Juliet as she emerges onto the balcony.
Romeo then states, "It is the east, and Juliet is the sun!" "It" refers to the balcony, therefore the balcony symbolizes an eastern land (eastern also representing the exotic) and Juliet is the sun that is rising out of the east, or literaly walks out onto the balcony (remember, the sun rises in the east and sets in the west).
Shakespeare uses light and dark images to symbolize good and evil. Juliet, being the brightest object, the sun, represents the best of all good things.
Romeo utters this Act II, Scene II, lines 2-3 "But soft! What light..." could be taken literally, that is, Juliet moves the curtain and Romeo sees the candle light filtering through. Or you may see this as symbolic, that is, Julia's "soft" womanliness and the "light" that Romeo senses she radiates.
Romeo says that in Act II, Scene 2. To extend the quote:
But soft! what light through yonder window breaks?
It is the east, and Juliet is the sun!
He is using a metaphor to describe Juliet and his feelings for her.
Romeo says the quote "But, soft! What light through wonder window breaks".
Romeo is using personification for the light. Since a light cannot break a window, it would be used for personification. He is trying to say that the light can be seen through the window.
he also uses metaphor for Juliet. Soft is referred to as Juliet, but there is no "like" or "as" which is the definition of a metaphor.
He is saying that juliet is like the sun so beautiful in her beauty...ya