bigdata refers to a collection of data whose contents cannot be crawled, managed and processed by conventional software tools in a certain period of time. Big data has five characteristics, namely, Volume, speed, Variety, low Value density and authenticity. It has no statistical sampling method, but only observes and tracks what happens. The usage of big data tends to be predictive analysis, user behavior analysis or some other advanced data analysis methods.
Gartner, a research institution of "Bigdata", gives such a definition. "Big data" is an information asset that needs new processing mode to have stronger decision-making, insight and process optimization ability to adapt to mass, high growth rate and diversification. [The definition given by McKinsey Global Institute is: a data set with a scale far beyond the capabilities of traditional database software tools in acquisition, storage, management and analysis, which has four characteristics: massive data scale, rapid data flow, diverse data types and low value density.