Https://www.codecademy.com/courses/react-101/lessons/react-jsx-advanced/exercises/jsx-map

**Hi, please i don’t understand the essence of two parameters here and also the function of the key attribute in the li element. the code is below **

import React from ‘react’;

import ReactDOM from ‘react-dom’;

const people = [‘Rowe’, ‘Prevost’, ‘Gare’];

const peopleLis = people.map((person, i) =>

// expression goes here:

  • {person}
  • );

    // ReactDOM.render goes here:

    ReactDOM.render(

      {peopleLis}
    , document.getElementById(‘app’));