title: What is use of curly braces in an ES6 import statement?
body: <p>I can see there are two different ways to import:</p>
  <pre><code>import React from 'react'
  import { render } from 'react-dom'
  </code></pre>
  <p>The second one has brackets. What is the difference between the two? And when should I add brackets?</p>