Comparing API Architectural Styles: SOAP vs REST vs GraphQL vs RPC
Two separate applications need an intermediary to talk to each other. So, developers often build bridges - Application Programming Interfaces - to allow one system to access the information or functionality of another. In order to integrate applications quickly and at scale, APIs are realized using protocols and/or specifications to define the semantics and syntax of the messages passed across the wire.
https://www.altexsoft.com/blog/soap-vs-rest-vs-graphql-vs-rpc/