React Element = JavaScript 객체

<div className="container">
  <h1>제목</h1>
  <p>내용</p>
</div>

{
  type: 'div',
  props: {
    className: 'container',
    children: [
      { type: 'h1', props: { children: '제목' } },
      { type: 'p', props: { children: '내용' } }
    ]
  }
}