title: What exactly is a "Prop" in React?
body: <p>I just started using React native on iOS to see how it feels like and I have a silly question..
  I see everyone talking about "Props", whenever I read an article or a tutorial, the author uses this term a lot and it's the same in the code. For instance, in class declarations I often see constructors like :</p>
  
  <pre><code>class MyClass extends Component {
  
      constructor(props) {
          super(props);
          this.state = { message: '' };
      }
  }
  </code></pre>
  
  <p>I can't find a clear explanation of what a prop is, could anyone enlighten me about that ?</p>