*2.1. The Concept of Real Estate Big Data*

For real estate, the data market is of great significance. In the history of Gangnam mentioned above, the real estate market is diversifying and diversifying, moving back and forth between rising and falling curves. Data is a very important factor in the real-time analysis of this diversifying real estate market. However, it will be helpful to use analysis and prediction only when data is generated in each form suitable for real estate market analysis. In the real estate market, real estate data is largely divided into three elements. First, financial data includes information on real estate investment trust companies and REIT-related stocks (Real Estate Investment Trust). The second is transactional data, including real estate sales, mortgage loans that loan long-term housing funds by issuing mortgage securities as collateral for real estate, and financial data such as leases, prices, and taxes. Finally, physical data includes real estate land or structure information, such as real estate structural characteristics or location data. Thus, three types of financial, transactional, and physical data are considered to be real estate data [5,6].
