"구형의 세계의 공" refers to a spherical object that represents a model of the Earth. This concept illustrates how the Earth is shaped like a ball, allowing for a better understanding of geography and navigation. The spherical shape helps visualize the planet's features, such as continents and oceans. In this model, the Earth's rotation and its position in space can also be demonstrated. The concept is essential for various fields, including geography, astronomy, and cartography. By using a globe, people can easily grasp the relationships between different locations and the Earth's physical characteristics.