Answer:
Application Programming Interface (API).
Explanation:
Application Programming Interface (API) is a term used to describe the method external organizations, systems, and "devices use to interact with the blockchain."
In Computer programming, an Application Programming Interface (API) can be defined as a software intermediary which primarily allows two (2) software applications to communicate with each other.
Hence, it is a standard set of protocols which defines the type of requests or call a software program makes, how it makes them, accepted data format, programming language used, authentication, encryption etc.
