Big Data consists of datasets that grow so large that they become awkward to work with using traditional database management tools. Difficulties include capture, storage, search, sharing, analytics and visualizing.
This trend continues because of the benefits of working with larger and larger datasets allowing analysts to "spot business trends, prevent diseases, combat crime", as a consequence new storage models (columnar, key-value, document oriented ...) are required.
Great part of the success of companies like twitter, facebook, groupon, i.e. … lies in the efficient use of Big Data techniques.