Big data has four characteristics, namely: Volume, Variety, Velocity and Value, which are generally called 4V.

1. The characteristics of big data are first reflected in the "big", from the first Map3 era, a small MB level of Map3 can meet the needs of many people, but with the passage of time, the storage unit from the past GB to TB, and even now the PB, EB level.

With the rapid development of information technology, data began to grow explosively. Social networks (microblogging, Twitter, Facebook), mobile networks, a variety of smart tools, service tools, etc., have all become sources of data. Taobao's nearly 400 million members generate about 20 terabytes of commodity transaction data every day; Facebook's approximately 1 billion users generate more than 300 terabytes of log data every day.

There is an urgent need for intelligent algorithms, powerful data processing platforms, and new data processing technologies to count, analyze, predict, and process such large-scale data in real time.

2. Diverse. The wide range of data sources determines the diversity of big data forms. Any form of data can have a role to play, the most widely used is the recommender system, such as Taobao, NetEase cloud music, today's headlines, etc., these platforms will be analyzed by the user's log data, so as to further recommend the user's favorite things.

Log data is structured obvious data, there are some data structure is not obvious, such as pictures, audio, video, etc., these data cause and effect relationship is weak, it is necessary to manually label it.

3. High speed. The generation of big data is very rapid, mainly through the Internet transmission. Everyone in life is inseparable from the Internet, which means that every day individuals are providing a large amount of information to big data every day.

And these data is the need for timely processing, because spending a lot of capital to store the role of small historical data is very uneconomical, for a platform, perhaps save the data only the past few days or within a month, and then far away from the data should be cleaned up in a timely manner, otherwise the cost is too great.

Based on this situation, big data has very strict requirements for processing speed, a large number of resources in the server are used to process and calculate data, many platforms need to do real-time analysis. Data is being generated all the time, and whoever is faster has the advantage.

4. Value. This is a core feature of big data. A small percentage of the data generated in the real world has value.

Compared with traditional small data, the biggest value of big data lies in the fact that by mining from a large amount of irrelevant data of various types, the data that is valuable for the predictive analysis of future trends and patterns can be analyzed in depth by machine learning methods, artificial intelligence methods or data mining methods.

Discovering new laws and new knowledge, and applying them to various fields such as agriculture, finance, and healthcare, so as to ultimately achieve the effect of improving social governance, increasing productivity, and advancing scientific research.