What's the term for when you replace "http://" with "myapp://" and have it open an external app? [duplicate]

Question

Sites like Steam and Rhapsody use steam://xxx and rhapsody://xxx in web pages, and when you click on them they cause specific actions in their (locally installed) client applications.

I would like to do this for something I'm working on and I just don't know what the search term is so it's hard to get started. What is this called?

Answer 1

The part before :// is called the URI Scheme. Historically, they were often called the protocol as their primary purpose was to setup communication (e.g. HTTP, FTP, TCP). These days, URI Schemes are used for a variety of purposes (launching apps; making payments; creating appointments).

The Internet Assigned Numbers Authority (IANA), best known for their role in allocating IP-addresses and managing the DNS root zones, also manages the list of well-known URI Schemes.

Besides the well-known URI Schemes, most platforms allow developers to register their own schemes:

• Windows - Registering an Application to a URI Scheme
• Android - Creating a custom intent