72 ITU‐T's Technical Reports and Specifications Ref. No. Category Definitions/Features Key concept/ Keywords Source 23 Academic A city \"connecting the physical infrastructure, the IT infrastructure, the social infrastructure, and the business infrastructure to leverage the collective intelligence of the city\". Interconnected IT, social, business infrastructure. Chourabi et al. (2012b) 24 Academic A city striving to make itself \"smarter\" (more efficient, sustainable, equitable, and liveable). Efficient, sustainable, equitable, liveable, standard of living. Chourabi et al. (2012c) 25 Academic Based on the exploration of a wide and extensive array of literature from various disciplinary areas, we identify eight critical factors of smart city initiatives: (i) management and organization.(ii) technology. (iii) governance. (iv) policy context. (v) people and communities, economy. (vi) built infrastructure. (vii) natural environment. Technology, governance, policy context, people and communities, economy, built infrastructure, and natural environment. Chourabi et al. (2012d)