On June 6, 2019, the Ministry of Industry and Information Technology (MIIT) issued 5G commercial licenses to China Telecom, China Mobile, China Unicom, and China Broadcast Network, marking that China officially ushered in the era of 5G commercial use. At the first anniversary of the issuance of 5G license on June 6, 2020, we carried out in-depth interviews with major industry enterprises in seek of the highlights of their IoT applications. A series of articles on 5G application cases were composed, forming a collection of classic industry cases that showcase the remarkable achievements of 5G in the special year of 2020.