CORS requests in cloud APIs

Even if you're not already using cloud storage and services, you will have heard about them. Amazon S3, Google Cloud Storage, Windows Azure, and IBM Cloudant all provide secure and scalable access to files, data, and other assets. Google APIs provide access to Google Products such as Drive, Search, Gmail, Translate, Google Maps, and YouTube, all hosted in the cloud on Google's infrastructure. In addition to storing files in Google Drive, you may have file storage in Box and Dropbox.

All of the APIs for these services support cross-domain requests with CORS. Using CORS can simplify your application, making proxy forwarding unnecessary. Keep in mind that you can also implement CORS with custom code for cases when the APIs don't support some of these platforms; however, it's usually better to use API methods when they are suitable.

Although the APIs and methods may change over time, having a sound understanding of CORS will help you implement cross-domain requests...