Many of us may have experienced the surprise of seeing recommended（推荐的） songs after listening to certain songs on a music app. When we open shopping websites, we are more likely to see things that we might want to buy.
This is based on data （数据）. Data is not only about numbers, but also information from almost every part of our lives：our location, shopping habits and interests. All of these are called "big data".
President Xi Jinping called for China to speed up its big data level in order to better serve social and economic（经济的） development and improve people's lives. He also asked for greater use of big data in areas like education, social safety and transportation.
In the past few years, we have seen big data being used more often in China. The role it plays in tourism is just one example. The data travelers share online is providing the tourism industry with a lot of information about the country'sscenic areas. After the data is analyzed （分析）, different scenic areas can create their own online information for other travelers to see. The information not only tells travelers' reviews, but also tells the scenic areas where services need to be improved.
Big data is important for economic development. With a growth rate of 30 percent, sales of big data services and products in China will reach l trillion （万亿） yuan yearly.
