"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.

Inizia dalla pagina “Your First Component” all’indirizzo https://react.dev/learn/your-first-component e individua la frase che contiene “instead of nesting definitions.”. Esamina la pagina collegata “Passing Props to a Component” per avere il contesto, quindi chiarisci cosa significa annidare le definizioni e perché si preferiscono le props. Il lavoro è completato quando un utente React può comprendere la frase e le indicazioni previste per il passaggio dei dati.