Urbanization refers to the process through which an increasing proportion of a country’s population begins to live in towns and cities, leading to the physical, demographic, social, and economic transformation of rural landscapes into urban settlements. It is a direct outcome of industrialization, economic development, and demographic changes, often linked with modernization and globalization. Urbanization is not merely the expansion of cities; it is also the growth of urban lifestyles, institutions, governance, and socio-economic systems. Historically, urbanization has been associated with progress, as cities become centers of commerce, culture, innovation, and opportunities. However, rapid and unplanned urbanization brings along serious challenges that affect sustainability, human well-being, and the environment. In the context of sustainable development and smart cities, understanding the issues and challenges of urbanization is crucial to ensure that urban growth aligns with ecological balance, economic inclusivity, and social equity. One of the foremost issues of urbanization is the problem of overpopulation in cities. As people migrate from rural to urban areas in search of better employment, education, and healthcare, cities often fail to accommodate the rapid influx. This results in overcrowded neighborhoods, informal settlements, and slums where basic amenities such as clean water, sanitation, and housing are inadequate. Overpopulation increases the demand for urban services beyond the carrying capacity of cities, straining infrastructure and public resources. The urban poor, particularly migrants, often live in unsafe conditions, leading to social marginalization and vulnerability. Housing shortage is another serious challenge tied to urbanization. The high cost of land and real estate in cities prevents many people from accessing formal housing. As a result, informal settlements proliferate, which lack proper sanitation, electricity, drainage, and waste disposal facilities. Such unregulated housing patterns contribute to urban sprawl and the degradation of land resources. Inadequate housing policies and slow implementation of affordable housing schemes further intensify the problem, making shelter insecurity a persistent urban issue. Transportation and mobility represent another critical area affected by urbanization. With the rapid increase in urban population and private vehicle ownership, cities face the problems of traffic congestion, air pollution, and inefficient public transportation systems. Congested roads reduce productivity, waste time, and contribute to mental stress for commuters. Moreover, the dominance of fossil-fuel-based vehicles worsens air quality, leading to severe health issues like respiratory diseases. Sustainable mobility solutions such as mass transit systems, cycling lanes, and pedestrian-friendly designs are often neglected