Most messages sent between Web services are coded in XML._____ are programming hooks or guidelines, published by organizations tell how other programs can get a service to perform a task, such as send or receive data.
The answer is "Application programming interface(APIs)".
Explanation:
API is a series of routines, set of rules or methods for the development of the application. It uses the graphical UI element software for utilization.
It defines how the components can communicate with applications in theory.
It is interlinked to an external software network for apps, which have access to its software and services.