What does {props.children} mean in this case?

  2 import React from 'react';
  1 import PropTypes from 'prop-types';
3   import GuestName from './GuestName';
  1
  2 const Guest = props => (
  3   <li>
  4   ¦ <GuestName
  5   ¦ ¦ isEditting={props.isEditting}
  6   ¦ ¦ handleNameEdits={e => props.setName(e.target.value)}>
  7   ¦ ¦ {props.name}
  8   ¦ </GuestName>
  9   ¦ <label>
 10   ¦ ¦ <input
 11   ¦ ¦ ¦ type="checkbox"
 12   ¦ ¦ ¦ checked={props.isConfirmed}
 13   ¦ ¦ ¦ onChange={props.handleConfirmation}
 14   ¦ ¦ />
 15   ¦ ¦ Confirmed
 16   ¦ </label>
 17     <button onClick={props.handleToggleEditting}>
 18       {props.isEditting? "save": "edit"}
 19     </button>
 20   ¦ <button>remove</button>
 21   </li>
 22 );
 23
 24 Guest.propTypes = {
 25   name: PropTypes.string,
 26   isConfirmed: PropTypes.bool.isRequired,

1   import React from 'react';
  1 import PropTypes from 'prop-types';
  2
  3 const GuestName = props => {
  4   if (props.isEditting) {
  5   ¦ return (
  6   ¦ ¦ <input
  7   ¦ ¦ ¦ type="text"
  8   ¦ ¦ ¦ value={props.children}                    // here
  9   ¦ ¦ ¦ onChange={props.handleNameEdits}
 10   ¦ ¦ />
 11   ¦ );
 12   }
 13
 14   return <span>{props.children}</span>;                     // and here
 15 };
 16
 17 GuestName.propTypes = {
 18   isEditting: PropTypes.bool.isRequired,
 19   handleNameEdits: PropTypes.func.isRequired
 20 };
 21
 22 export default GuestName;