The amount of information created worldwide in digital
format surpassed 1.8 zettabytes (1.8 billion terabytes) during
2011. By 2020, the world will generate 50 times that amount.
This digital data is generated by “numerous devices in numerous
forms: remote sensors, online retail transactions, text documents,
e-mail messages, web posts, camera and video images,
computers running large-scale simulations, and scientific
instruments such as particle accelerators and telescopes” [5].