Big Data (Big Data) refers to "massive, complex collections of data that cannot be extracted, stored, searched, ****enjoyed, analyzed, and processed with existing software tools." The industry usually uses the 4 Vs (i.e. Volume, Variety, Value, Velocity) to summarize the characteristics of Big Data.

One is the huge volume of data (Volume). As of today, the volume of data for all printed material produced by humans is 200PB (1PB=210TB), while the volume of data for all words spoken by all humans throughout history is about 5EB (1EB=210PB). Currently, the capacity of a typical personal computer hard disk is on the order of terabytes, while some large corporations are approaching EBs of data.

The second is the variety of data types (Variety). This variety of types also allows data to be divided into structured data and unstructured data. Compared to the text-based structured data that was easy to store in the past, there are more and more unstructured data, including web logs, audio, video, pictures, geolocation information, etc. These multiple types of data put forward higher requirements on the processing capability of the data.

Third, low value density (Value). Value density is inversely proportional to the size of the total amount of data. Take video as an example, a 1-hour video, in continuous uninterrupted monitoring, useful data may be only one or two seconds. How to complete the data value "purification" more quickly through powerful machine algorithms has become an urgent problem in the context of the current big data.

Fourth, processing speed (Velocity). This is the most significant feature of big data differentiated from traditional data mining.