The present time is the time of digital transformation. New smart or intelligent devices and technologies influence our everyday life and have a great impact on our environment. Such paradigms as Internet of Things (IoT) and Smart Systems are also unavoidable undergoing changes and modifications. Especially the domain of Smart Cities is getting more and more attention and is benefiting from the outcomes of digital transformation. In this paper we focus on the evolution of technologies in this fields and provide an overview over a selection of numerous applications.