What is the difference between token authentication and authentication using cookies?
I am trying to implement the Ember Auth Rails Demo but I do not understand the
I believe that there is some confusion here. The significant difference between cookie based authentication and what is now possible with HTML5 Web Storage is that browsers are built to send cookie data whenever they are requesting resources from the domain that set them. You can't prevent that without turning off cookies. Browsers do not send data from Web Storage unless code in the page sends it. And pages can only access data that they stored, not data stored by other pages.
So, a user worried about the way that their cookie data might be used by Google or Facebook might turn off cookies. But, they have less reason to turn off Web Storage (until the advertisers figure a way to use that as well).
So, that's the difference between cookie based and token based, the latter uses Web Storage.