Type of component children in React

There are two common types to describe the children of a component.

1. React.ReactNode: it is a union of all the possible types that can be passed as children in JSX, it is a very broad definition of children:

interface ModalRendererProps {
  title: string;
  children: React.ReactNode;
}

1. React.ReactElement, same as React.JSX.Element: it is only JSX elements and not Javascript primitives like strings or numbers:

interface ModalRendererProps {
  title: string;
  children: React.ReactElement;
}

See https://react.dev/learn/typescript