Smart cities are connected urban environments which do have a potential to improve efficiency, ensure quality of life for their citizens and enhance sustainability by integrating cutting edge technologies. Smart cities are at the forefront of urban development, utilizing state-of-the-art technologies to solve pressing environmental issues along with enhancing the quality of life for citizens. This article explores the complex relationship that exists between sustainability and smart city projects, explaining how both programs have the potential to transform urban living. Through the examination of technical frameworks like Internet of Things (IoT), big data analytics and artificial intelligence, we reveal the revolutionary potential of smart cities in terms of improving environmental sustainability and resource management. We also examine the challenges which are there in the way of fully realizing these advantages, including as data privacy concerns, technology interoperability issues, and the requirement for strong legal frameworks.