title: What is a snapshot in Flutter?
body: <p>I've been using a Firebase database in my project. I've been following a tutorial, and when returning widgets to the future builder it says to use:</p>
  <pre><code>if(snapshot.hasError) {
      // Cannot connect to database
  }
  else {
      // Return widgets as normal
  }
  
  </code></pre>
  <p>I have checked the Flutter documentation and they say a snapshot is:</p>
  <blockquote>
  <p>Immutable representation of the most recent interaction with an asynchronous computation.</p>
  </blockquote>
  <p>But what does this mean, and why does the above code make sense?</p>