The difference comes from the scale, scope and the tools available to each person.
Writing a popular movie can change the world and the way that people think about a particular subject. This is the toolset of those well-versed and skilled in the literary and theatrical arts.
An invention, like zero-emissions energy generation can change the world. When energy cost very little, and has no impact on the environment, then standard of living can rise drastically. This is the toolset of the mathematical and engineering-minded.
You can change the world by selling an idea or invention that someone came up with. This is the toolset of the people person’s. The influencers. The marketers.
You can change the world by complimenting others, supporting other and being a pleasant attitude in a harsh environment. This is the toolset of the caretakers of the world. Not necessarily in the medical context, but that certainly applies too.
There are all types that make the world go around. Each one supports the others in a vast circle that can be hard to see. Some will do so at huge scales, some will do so at minor scales, but nonetheless opportunity exists for everyone.