Okay kiddo, so you know how sometimes people are treated differently or unfairly based on things like the color of their skin or where they come from? That's called racial discrimination, and it's a really bad thing that can cause a lot of pain and problems.
The declaration on the elimination of all forms of racial discrimination is a special promise that lots of countries made to each other. They said that they will work really hard to get rid of racial discrimination everywhere, so that everyone can be treated fairly and equally no matter who they are or where they come from.
This promise is important because it means that people are starting to realize that it's not okay to treat others differently just because they have a different skin color or come from a different place. Hopefully, with this promise, more and more people will start treating each other with love and respect, no matter what.