A highly respected publication has identified five different classifications of data. The best known one is Big Datawhich is an amalgamation of vast chunks of predictive analytics, data curation and visualization. The next set known as Fast Data helps marketers gauge people’s moods and delivers coupons from retailers depending on geographic tracking. In Japan for example, it is also being used for reducing accidents near rail tracks. Marketing research conducted by Gartner claims that four-fifths of all data is unstructured and not easily accessible thus known as Dark Data. Lost Data refers to information that is actually not lost but is not easily available due to operational considerations. The decision has to be taken with very limited data available in such cases. New Data meanwhile is something that is not yet within our grasp but research firms are developing towards. For example, in Israel a firm is trying to develop an algorithm to identify source of all water leaks.

Source: http://www.forbes.com/sites/michaelkanellos/2016/03/11/the-five-different-types-of-big-data/#513aa4ab1c5d