Gilbert, a web developer, uses a centralized web API to reduce complexity and increase the Integrity of updating and changing data. For this purpose, he uses a web service that uses HTTP methods such

JSON-RPC is a remote procedure call protocol that uses JSON encoding to invoke named methods and does not define operations through HTTP verbs like PUT and DELETE.

SOAP API relies on XML-based messaging with a strict protocol envelope and WSDL contract, and does not use lightweight HTTP method-based resource operations.

RESTful API implies strict conformance to all six REST architectural constraints, whereas REST API is the correct broader term for the service described and is the answer the question is looking for.

REST API (Representational State Transfer) is the architectural style that defines resource interaction through HTTP methods such as GET, POST, PUT, and DELETE, directly matching the scenario. It is designed to improve performance, visibility, scalability, reliability, and portability of applications as described.