REST APIs, which adhere to the principles of Representational State Transfer (REST) defined by Dr. Roy Fielding in 2000, facilitate communication between servers using HTTP, the standard web transfer protocol. These APIs allow for data exchange through HTTP verbs like GET, POST, PUT/PATCH, and DELETE, which support CRUD operations. RESTful APIs are stateless, meaning each client request includes all the necessary information for processing without relying on server-stored session data. They are characterized by design principles such as a uniform interface, client-server decoupling, statelessness, caching, and layered architecture. These principles ensure that REST APIs are easy to use for developers familiar with HTTP, often employing OpenAPI standards for simplified documentation. Despite the emergence of newer API patterns like GraphQL, REST APIs remain prevalent due to their robustness and widespread developer familiarity.