In the traditional industrial division, which industry does real estate development belong to? Why? O(∩_∩)O Thank you

Real estate is an industry that provides housing sales and after-sales service for residents, and its nature is biased towards sales and service industry, so it belongs to the tertiary industry. Although the construction industry is closely related to the real estate industry, the general developers and builders are cooperative and managed and accounted separately, so the construction industry belonging to the secondary industry does not affect the industry classification of the real estate industry.