The world is the entire planet Earth and everything on it: all the continents and oceans, all the people and animals, all the cities and wilderness areas. When you think about the world, you're thinking about the whole globe spinning through space.

The word also refers to everything connected to a particular subject or area of life. When someone says “the world of music” or “the world of sports,” they mean the people involved, the places where it happens, and the way things work in that area. A scientist might spend her career exploring the world of marine biology, studying ocean life and its mysteries.

The world can also mean your own personal experience of life. When you make a new friend, they become part of your world. When something goes wrong, it might feel like your world is falling apart, even though the planet itself is fine. When parents tell a child “you mean the world to me,” they're saying that child is the most important thing in their life.

People often talk about making a difference in the world or changing the world, meaning they want to improve life for others or solve important problems. The world is both the stage where human history unfolds and the home we all share, filled with millions of different cultures, languages, and ways of living.