"Instead of nesting definitions" in docs

On this page: https://react.dev/learn/your-first-component

When a child component needs some data from a parent, pass it by props instead of nesting definitions.

all of a sudden, it says, "instead of nesting definitions". Can you explain in the docs more what is "nesting definitions" and how does it work to "attempt to pass some data and doesn't work or shouldn't be done"? I have never heard of "nesting definitions" after working with React for a few years.

Comienza con la página “Your First Component” en https://react.dev/learn/your-first-component y localiza la frase que contiene “instead of nesting definitions.”. Revisa la página enlazada “Passing Props to a Component” para obtener contexto y, después, aclara qué significa anidar definiciones y por qué se prefieren las props. El trabajo estará terminado cuando un usuario de React pueda entender la frase y la orientación prevista para pasar datos.