Big data: datasets whose size is beyond the ability of typical database software tools to capture, store, manage, and analyze.

• The definition varies by sector, depending on the available software tools and dataset sizes in a particular industry.
• Big data today ranges from a few dozen terabytes to multiple petabytes (thousands of terabytes).
• Different views: to computer science it is data that will not fit in main memory; to statistics it is data with a large number of observations and/or features.