title: React + TypeScript: 'React' refers to a UMD global but the current file is a module. Consider adding an import instead. (Justification)
body: <p>We are using React and TypeScript in our current project and I come across below behavior.</p>
  
  <pre><code>import React, { Component } from 'react';
  </code></pre>
  
  <p>I replace the above line with the one below since it seems to be using <code>Component</code> import only.</p>
  
  <pre><code>import { Component } from 'react';
  </code></pre>
  
  <p>And I was thrown below error</p>
  
  <blockquote>
    <p>Error: 'React' refers to a UMD global but the current file is a module. Consider adding an import instead.</p>
  </blockquote>
  
  <p>I tried looking it up on Stack and GitHub, found few articles and discussion but still unclear about why it's happening.</p>
  
  <p>Would be more interested in whether React or Typescript is throwing it and WHY ? Not the ways to fix it.</p>
  
  <p>Also some light around UMD, why it's used here ?</p>