Cities, as the crucible and the hub of human innovation and advancement, face critical changes in their fundamental role. Through a smart city, the global community has strived to converge and integrate environmental, digital, bio, and financial technologies to solve various urban problems. It is imperative to understand the true value and implementational practicality of key technologies in their full depth for their deployment in the construction of new smart cities or in the regeneration of legacy cities to advanced smart ones in the right way.