Urbanization is the process by which an increasing percentage of a population lives in cities and suburbs. This trend, which began to accelerate during the Industrial Revolution, is driven by the search for better employment opportunities and access to services. While cities are often engines of economic growth and cultural innovation, rapid urbanization can strain existing infrastructure and lead to the growth of informal settlements, such as slums. Furthermore, urban environments often face significant environmental challenges, including air pollution and inadequate waste management. Some urban planners advocate for 'smart growth' policies that prioritize high-density development and public transit to mitigate these negative effects. Despite these challenges, the United Nations predicts that nearly 70 percent of the world's population will live in urban areas by 2050, making sustainable urban planning a critical global priority.