ABSTRACT
With the movement of people from the countryside to urban cities, the need to develop services increases as well. The development of services is necessary to accommodate the population growth in terms of transportation, education, and health. Smart cities meet these issues using a comprehensive echo system incorporating smart technologies and enhancing citizens' quality of life. In this paper, we focus on six dimensions of smart cities: living, environment, governance, economy, people, and transportation. In light of these dimensions, we review six smart cities around the world: Dubai, Tokyo, Singapore, Hong Kong, Seoul, and Reykjavik. Moreover, we review Riyadh, Saudi Arabia, as a city aspiring to be fully smart in each dimension. Lastly, we elaborate on the health aspect with regard to the response to the COVID-19 pandemic in all cities under consideration. © 2022 IEEE.