Several attempts have been undertaken to define the domains that constitute smart cities. A smart city is a city that performs well in six domains, smart economy, smart people, smart governance, smart mobility, smart environment, and smart living, building upon endowments and the active participation of citizens. Building upon the six domains has added smart buildings to the list, highlighting how all of the domains need to work together as a city is a single organic whole.
Chourabi et al., 2012 established eight domains of a smart city: Management and organization, technology, governance, policy context, people and communities, economy, built infrastructure, and natural environment.
Some researchers have proposed different sets of domains, Albino et al. (Albino et al., 2015) have surveyed and described several proposals of domains of a smart city, including the aforementioned lists of domains. Following is the most common elements that emerge from the proposed domains are
(i) networked infrastructures enabling political efficiency and social development,
(ii) promotion of urban development and growth via economy and culture,
(iii) social inclusion, and
(iv) the well-being of the natural environment.
Smart city domains may be categorized into soft domains and hard domains.
Soft domains refer to the intangible characteristics of smart cities, such as smart citizens and smart living.
Hard domains refer to tangible characteristics, such as smart environment and smart mobility.
Soft domains, being intangible, are more difficult to measure than hard domains. Thus, a city may be more motivated to invest in hard domains because the results are easier to measure. The explanatory analysis has found that a smaller percentage of cities invest in the soft domains, compared to the higher percentage of cities that invest in the hard domains. Nevertheless, the decision to develop a domain of a smart city will depend on the necessities and country-specific factors of a city.
From a closer look, smart cities have been criticized. It has become common for cities to declare themselves smart for promotional purposes, focusing on informational business interests while hiding growing social polarization. According to Law and Lynch, one of the fundamental challenges for smart cities in 2019 is to promote fair outcomes for all residents. Smart cities should prioritize human beings and living beings in general, as well as the urban context. IoT frameworks, such as IoT applications, should facilitate the ease of life and convenience of communities while imitating the natural growth of urban environments.