title: When to use Ajax vs Json for Javascript events?
body: <p>I'm not so familiar with Ajax but I keep hearing Json mentioned as some kind of competing option. Is there a rule for when to use one versus the other?</p>
  
  <p>I'd like to process Javascript events in my app and update the front-end dynamically from the app but I'm not sure whether I need to use Ajax or Json for this.</p>