Answer:
The opening scene of Romeo and Juliet is of great dramatic significance for a number of reasons. First of all, there's a lot of action involved, which immediately grabs our attention. This is a very dynamic play with quite a lot going on at any given time, and the opening scene establishes this fundamental dynamism. Also, we're thrown right into the thick of things. The very first thing we witness is a street brawl between partisans of the two warring families. The fact that the young men involved in the brawl are but lowly servants immediately shows us just how deeply the hatred between the Montagues and the Capulets runs. All stations in society are affected by this never-ending feud, not just the nobility.
The opening fight also establishes the general theme of conflict.The theme is developed.