REST is a style of development for exposing data through HTTP in a way that is easy to consume and produce. It uses HTTP status codes to indicate the status of requests and responses, such as codes in the 2xx range indicating success, 4xx for client errors, and 5xx for server errors. Examples show how specific status codes like 201, 204, 301, 409 and 501 should be used in REST services to clearly convey request status and direct client behavior.