These days, there is a lot of data we can find from various sources. Customer profiles, e-commerce transactions, sensor data from IoT, and social media are massive data. Regarding the data from IoT,  Gartner reported that 8.4 billion connected things were used in 2017. For more information, refer to https://www.gartner.com/newsroom/id/3598917. Gartner predicts that connected things, such as IoT devices, will reach 20.4 billion by 2020. 

As we know, there are a lot of new IoT platforms to implement IoT projects. These boards can generate sensor data. Each data has its own data type that represents sensor information, such as temperature and humidity.

The following figure illustrates that data comes from any source, such as sensor, transaction, social media, news, email, and medical. This data is regarded as massive data in the internet era: