The article explores how urban land in cities changes over time and why. It looks at how cities in China and around the world are growing and how this affects the way land is used. The researchers found that urban land changes because of things like new industries, technology advancements, and how people in the city live and work. They also discovered that cities expand outwards and change the layout of land within the city. By understanding these changes, cities can plan better and use land more efficiently as they grow.