Every Second some kind of a new data is being created somewhere in the world and when you all all of these together you get such large amounts of data which is actually not possible to evaluate and decipher using traditional tools.
Big Data might be generated through the sensors in gambling casinos, while moving around with your smart phone, while browsing the internet, through sensors in the oceans or on your pet's collar, etc.
And organizing these kinds of data becomes important because that helps in creating a kind of transparency which can be effectively used to improve efficiency.
Also, it is important to organize these data so that with all that unorganized data at hand, important information is not leaked into the wrong hands.