In the 21st century, the concept of a “smart city” is more than just a buzzword or an ideology, it’s a necessity. With the increasing and unpredictable demands of urbanization, individuals from the public and private sectors are turning to emerging technology to tackle the many implications of a growing urban sprawl. From the "Big Apple" to a desert metropolis, smart cities around the world are innovating solutions to problems like overcrowding, congestion and pollution in an attempt to make urban life as efficient as possible. CNN explores how these solutions, both big and small, use technology like cloud computing, blockchain solutions, biometrics and artificial intelligence to revolutionize city life as we know it.