The easiest way to get familiar with our APIs is through the interactive swagger examples. You don't need to obtain your own API key for that, just select the API of interest and hit "Try it out!" button. The interactive API will teach you how to construct a request, and you will see the expected response on the spot.
Note: The example API key used in interactive APIs is meant for demonstration purposes only; please obtain and use your own API key with your application. If you'd like to use your own API key with Interactive APIs, you can do so by pasting it into the "apiKey" field. (In case you wonder: by default, APIkeys issued by us are configured for cross-origin resource sharing from https://dev.elsevier.com using W3C CORS.)