Big Data is a notion that includes a great amount of often diverse and unstructured information, methods for storing and processing it and also certain software and hardware.

The classic definition is based on three Vs: volume, velocity, variety. Recently another criterion has been added to these — value (veracity). Big Data volume means great amount, velocity tells us about high growth rate of this amount and also of the need to process it quickly, variety indicates variability of the information which has or lacks structure. Big Data value means relevance, propriety, credibility and accuracy of the information or, vice versa, its uncertainty.

The definition of Big Data appeared not so long ago — in the autumn of 2008. It was created by the editor of «Nature» scientific journal Clifford Linch, who was trying to forecast the outcome of sudden, ‘explosive' growth of information. Two years later the first software solutions appeared and one year later dealing with the problem of Big Data became customary for big players at the IT market. In 2013 lectures on big data and data analytics in IT and other industries were being read at the Universities. Nowadays some analysts even talk about «Big Data Era».

Sources of information in big data and data analytics industries are research equipment sensors, purchase history of off-line and on-line shops, data on patients' health and illnesses, security cameras records, weather data. Big Data source in IT is information about user behavior in social media.

Where can large amounts of information be used? Big data analytics are used in medicine, education, earthquakes and traffic jams forecasting, ecology and even Hollywood and Formula-1. Of course, Big Data in IT also play an important part. The main values of big data are in forecasting consumer demand on the basis of purchases already made, which results in clients being more satisfied.

Big Data Industry is in controversial condition at the moment. On one hand, projects in this sphere are often run in pilot mode. But on the other hand, leading experts, for example, Jessica Goepfert from IDC, claim that nowadays we should speak not only about Big Data in IT industry, but about the fact that they will play one of the key roles in any sphere.

Analytical consulting company IDC forecasts substantial growth of Big Data and business analysis in the coming years. By 2019 the market will have grown in half and will amount to 187 billion dollars. The head of Dell Michael Dell makes even bolder statements. According to him, the sphere may reach 1 trillion dollars. At the same time over 50% of Big Data market will fall to the service sphere. The main stimulus for Big Data development will be coming from large companies with the staff of more than 500 employees. Volume of Big Data, by modern standards, is enormous and is often measured in exabytes.

Starting from 2008 and till 2014 big data trend was growing rapidly and then started to slow down. Gartner consulting company excluded Big Date from popular trends, because, according to them, the term stopped being abstract and became an everyday reality for large business and also began to ‘blur', differentiate into different technologies (the most important of which is the Internet of things).

Big Data values can hardly be overrated nowadays. Big Data permanent growing raises new issues, such as ethics and ecology of Big Data in business. If big business players want to stay at the market they will need to develop this concept, because big data analytics is one of the foundations for digital transformation of business.