• Request Verbs – [GET, POST, PUT, DELETE] • Request Headers – These are additional instructions that are sent with the request. These might define what type of response is required or authorisation details. • Request Body - Typically sent as the request body in the format of JSON or XML. • Response Body – Returned by the API, this might be a JSON or XML document. • Response Status codes – These codes are issues with the response and give the client details on the status of the request.