万博, or the World Expo, is a large international exhibition that showcases the achievements of nations. It is held every few years in different cities around the world, featuring pavilions from participating countries that highlight their culture, technology, and innovations. The event aims to promote global cooperation and cultural exchange. The first World Expo took place in 1851 in London, and since then, it has evolved into a platform for countries to present their advancements and ideas. Each expo has a specific theme, such as sustainability or innovation, encouraging nations to collaborate on global challenges and share solutions.