title: What is the caret sign (^) before the dependency version number in Flutter's pubspec.yaml?
body: <p>In the <code>pubspec.yaml</code> file of my Flutter project there is a caret (<code>^</code>) before the version number of some of the dependencies.</p>
  
  <pre><code>dependencies:
    flutter:
      sdk: flutter
    cupertino_icons: ^0.1.2
    english_words: ^3.1.5
  </code></pre>
  
  <p>What is its purpose? What does it mean?</p>
  
  <p><strong>Notes</strong></p>
  
  <ul>
  <li>I looked in the <a href="http://yaml.org/spec/1.0/" rel="noreferrer">yaml documentation</a> but I didn't see anything that made sense. </li>
  <li>Related: <a href="https://stackoverflow.com/questions/50146809/what-does-caret-sign-do-in-dart">what does Caret sign do in Dart</a> (but it isn't an XOR operator here)</li>
  <li>Related: <a href="https://stackoverflow.com/questions/50533553/in-flutter-dependencies-must-specify-version-number">In Flutter, Dependencies must specify version number?</a> (an answer pointed me in the right direction but the question is asking something different)</li>
  </ul>