These two phenomena are closely related. However, it's important to understand that one doesn't necessarily cause the other. It's a chicken-and-egg situation - we can't always say whether a high number of people living in urban areas leads to wealth, or if increased wealth causes more people to flock to cities.

Real-world Example: Let's take Dubai, which was once a small fishing village. It used to rely heavily on its pearl exports. However, the discovery of oil led to a rapid increase in wealth which, in turn, sparked urban growth as more people moved there for opportunities. But remember, it's not always so straightforward - sometimes people move to cities hoping for wealth, but wealth doesn't always follow.

Cities and towns aren't just hubs of population; they serve essential functions in the process of development.

• Commercially: They provide marketplaces and exchanges, helping shift economies from subsistence to cash crops.
• Industrially: Larger towns can stimulate development by providing opportunities for both skilled and unskilled labour.
• Politically: Towns may ignite nationalism and foster diversity through intermixing of ethnic, tribal and religious groups.
• Administratively: Towns can efficiently deliver services like health and education due to economies of scale.
• Socially: The intermixing in towns can lead to a gradual erosion of traditional rural beliefs and customs.

Real-world Example: The city of New York is a prime example. It's a commercial hub (Wall Street, anyone?), industrial centre (hello, Silicon Alley), and melting pot of various ethnic and religious groups. It's also known for its education and health institutions and, despite being a place of old and new traditions, it continuously shapes and reshapes social norms.

Cities also have their drawbacks, like pollution, destruction of ecosystems, poor living conditions, and high rates of unemployment, among other things. Other issues include insufficient housing, leading to the growth of slums and squatter settlements, overloaded transport systems, deteriorating infrastructure, and social problems like increasing crime and drug abuse.

Real-world Example: Mexico City demonstrates these challenges. Despite being one of the most important economic centres in Latin America, it grapples with air and water pollution, overpopulation, housing issues, and high crime rates.