URL Schemes (= Deep Linking = x-callback-url) is a hyperlink that links to a specific, generally searchable or indexed, piece of web content on a website (e.g., “http://example.com/path/page”), rather than the website’s home page (e.g., “http://example.com”)

x-callback-url is originally for handling errors and communication between different apps. Using x-callback-url, source apps can launch other apps passing data and context information, and also provide parameters instructing the target app to return data and control back to the source app after executing an action.

URLs are structured as follows:

scheme://user:password@host:port/path?query#fragment

References