The waiter analogy in the first tutorial set the meaning and function of APIs as clear as could be. I have always maintained that the use of everyday activities as references remain the most effective form teaching. Henceforth, that analogy will remain in my mind when I see the services of a waiter. I was so amazed about the power of the REST API and its possibilities. I will have to revisit most of the explanations at a later time to cement my understanding and its usage. But in all, the concept seem fairly simple and straight forward. I have been watching a few tutorials about the powerful symbiotic relationship between APIs and JSON. I was particularly impressed with this resource on REST API concepts and examples and how to make a API request (graph.facebook.com/youtube). I tried a couple of websites but got this error message.

{
   "error": {
      "message": "An access token is required to request this resource.",
      "type": "OAuthException",
      "code": 104,
      "fbtrace_id": "HuZcagOScRx"
   }
}