title: When should I run `react-native start`?
body: <p>Just getting started with React-Native (for the non-CRNA/Expo case) and it's not clear to me after reading the <a href="https://facebook.github.io/react-native/docs/getting-started.html" rel="noreferrer">react-native docs</a> or <a href="https://facebook.github.io/react-native/docs/understanding-cli.html" rel="noreferrer">Understanding the CLI</a> when it's appropriate to run <code>react-native start</code></p>
  
  <p><code>react-native start --help</code> simply says <code>starts the webserver</code>.  Running <code>react-native run-ios</code> also starts the same server except it also actually runs it in the simulator.</p>
  
  <p><strong>Question:</strong> When is it appropriate to run <code>react-native start</code> vs. just running the simulators directly (i.e. <code>react-native run-ios</code>)?</p>