title: Backbone js .listenTo vs .on
body: <p>What are the advantages and disadvantages of the following 2 lines of code? I don't understand why there are 2 different ways to do the same thing.    </p>
  
  <pre><code>this.listenTo(app.Todos, 'change:completed', this.filterOne);
  app.Todos.on('change:completed', this.filterOne);
  </code></pre>
  
  <p>Also when using .on, how do I determine is the default context?</p>