What is RESTful API?

RESTful API (Representational State Transfer Application Programming Interface) is an architectural style for designing networked applications. It relies on a stateless, client-server, cacheable communications protocol -- usually HTTP. RESTful APIs define a set of constraints, such as the use of standard HTTP methods (GET, POST, PUT, DELETE) to perform operations on resources identified by URLs. They are commonly used to build web services, enabling different software systems to communicate and exchange data in a standardized way.