REST vs RESTful APIs

REST is an architectural style for networked resources; “RESTful” describes an API designed around those constraints. The terms are often used loosely, but REST is not a protocol and it is not synonymous with “JSON over HTTP”.

A REST-oriented API gives resources stable URLs, uses HTTP methods and status codes meaningfully, keeps requests stateless from the server's perspective, and returns representations such as JSON. For example, GET /users/42 retrieves a representation and PATCH /users/42 requests a partial update. The exact URL shape is a design choice, not a certification test.

A practical API can use REST ideas without implementing every academic constraint, including hypermedia controls. Document authentication, validation, pagination, idempotency, error formats, and caching explicitly. Calling an endpoint “RESTful” does not make it secure or well-designed; clients still need timeouts, retries appropriate to the method, and careful handling of untrusted data.

Sources

• MDN — HTTP overview