title: Firebase - What is the API Key
body: <p>In Firebase, when we sign up , it gives us an API key for each firebase Url. But where is it used in a consuming application? The fireBase API does not provide any means to supply API Key.</p>
  
  <p><strong>Security</strong> : What prevents anyone to go ahead and write any object to the given firebase Url? How is the authorization managed?</p>