title: Understanding @Binding in SwiftUI
body: <p>I watched some WWDC videos and Apple docs about data binding, and according to my current understanding, @State as a property delegate will provide a binding connection between the view and the annotated property, for example:</p>
  
  <pre><code>@State var myText: String
  
  var body: some View {
    VStack {
      TextField($myText, placeholder: Text("input"))
      Text(myText)
    }
  }
  </code></pre>
  
  <p>This will bind <em>myText</em> with the content of the text field I added (i.e. one changes the other will follows up to update)</p>
  
  <p>However, though I know $myText refers to the binding type of Binding, I noticed that Binding is also a property delegate, and I noticed it appears in some code examples from Apple. I have no idea what this is used for as a property delegate. @State already does the binding work, then what do we need @Binding for?
  Apple docs suck for now about this.</p>