The specific goal of storming the Bastille was to take its stash of gunpowder. The storming of the Bastille, however, has come to represent the revolt against the French monarchy. The storming of the Bastille is regarded as the beginning of the French Revolution.
Tension between the citizens of France and its rulers had been growing for many years. The monarchy drained the country's finances building elaborate homes and throwing lavish parties, while common citizens struggled to survive. After rumors began spreading that King Louis XVI was plotting to overthrow the government reforms that were taking place, a group of common citizens rallied to prepare to take on the king's army.
The group faced an early dilemma because they had weapons but no ammunition. The Bastille, a prison that became a symbol of the tyrannical power of the French monarchy, housed a healthy supply of gunpowder. The crowd decided to attack the Bastille and overtake the guards. The endeavor was successful and incited a very large riot in which the Bastille's gunpowder supply was pirated and the group gained many more weapons. Several prisoners were also freed.
With the newly acquired gunpowder and arsenal of weapons, plus the addition of many more supporters who joined in on the riots, the crowd grew powerful enough to take on the monarchy, and the French Revolution began.