*Corresponding author Surabhi Shanker: Trinity Institute of Professional Studies, GGSIPU, New Delhi, Email: Dr.surabhishanker@gmail.com Digital Twins and Federated Learning for Smart Cities and Their Applications Surabhi Shanker Source Title: Demystifying Federated Learning for Blockchain and Industrial Internet of Things Copyright: © 2022 |Pages: 20 ISBN13: 9781668437339|ISBN10: 1668437333|EISBN13: 9781668437353 DOI: 10.4018/978-1-6684-3733-9.ch009 Abstract: The society is getting massive benefits from the advancement and Innovation in technology. Technology plays vital role in all aspect of our lives. The continuous developments in technology have saved countless lives and also have improved the quality of living. Digital twin is one of the innovations of today’s technology. It is the concept of virtual replica if physical object. As the Internet of Things (IoT) initiated to rise, it saw the implementation and fame of digital twins in other industries, due to its cost-effectiveness and ease of use. The concept of the smart city over digital twins is apparent. From urban planning to land-use optimization, it has the power to govern the city in an effective manner. Digital twins allow the replication of plans before implementing them, uncovering problems before they become a reality. Architectural parts that could be planned and scrutinized through digital tools include; housing, wireless networks antennas, solar panels, and public transport. Digital twins duplicate the physical model for remote monitoring, viewing, and controlling based on the digital format. It is actually the alive model of the physical systems which uninterruptedly adapts to operational changes based on the real-time data from various loT sensors and devices and predicts the future of the matching physical counterparts with the help of machine learning/artificial intelligence. A digital twin is a digital or virtual copy of a physical assets or products. The term digital twin was firstly invented by Dr. Michael Grieves in 2002. First of all NASA was used this technology for space exploration missions. Digital twins link the real and virtual world by gathering real time data from the installed sensors. The composed data is either locally decentralized or centrally stored in a cloud. The data is then evaluated in virtual copy of the assets. Once the information received from the simulation the parameters are applied to real assets. This integration of data in real and virtual representations helps in enhancing the performance of real assets. Digital twins can be used in various industries: Manufacturing, Automotive, construction, Utilities, healthcare. Digital twins are the next giant thing in fourth industrial revolution for the development of new products and processes.