A smart city finds ways to better serve its citizens, and brings together key urban systems, including energy grids, water management, waste systems, smart mobility and transportation based on the engineering applications. The smart cities should aim to strengthen the socioeconomic backbone of the city, so the subject needs to be addressed in multi-dimensional framework. Thus, different disciplines such as engineering, architecture, sociology, economics and urban design are practiced upon in order to design smart technology plans and systems. Even though innovative smart city projects offer sustainable, mobile, digital, safe infrastructures that enable flexibility to different needs still there is no consent about what really forms a city smarter. This paper considers smart cities as integrated models, and aims at disclosing major catalysts for socioeconomic development in smart city projects. Besides, discusses about the tools for urban development enabled by knowledge-intensive digital applications, the role of open data in smart mobility systems and nature-based solutions. Several dimensions and elements of the smart cities are defined based on the projects of five chosen cities located in different continents. Findings from each project about their critical systems, salient concepts and driving elements are utilized to conclude the study with triggers that can set cities on the path to becoming smart.