Worlds refer to distinct realms or environments that can be physical, conceptual, or fictional. In a physical sense, Earth is one world, while other planets like Mars and Jupiter represent different worlds within our solar system. Each world has unique characteristics, such as climate, geography, and potential for life. In a fictional context, worlds can be created in literature, movies, or video games, offering imaginative settings for stories. Examples include the Wizarding World of Harry Potter or the Star Wars universe. These worlds often have their own rules, cultures, and histories, enriching the narratives they contain.