If the SAP system has the client role, interface IF_HTTP_CLIENT of class CL_HTTP_CLIENT is implemented. IF_HTTP_CLIENT serves as an interface for gaining access to data structures, so that request and response data can be processed. It also ensures communication between client and server, in this case from the perspective of the client.
An object of the class CL_HTTP_CLIENT, a client control block, is created for every outgoing request, as described above. Just like an object of the class CL_HTTP_CLIENT, this object contains the data structures IF_HTTP_REQUEST and IF_HTTP_RESPONSE for the HTTP request and HTTP response data. It also provides interface references in its own interface to these data structures: Attributes REQUEST and RESPONSE. In this case, the response part is empty when the request is sent.
The interface IF_HTTP_CLIENT contains its own attributes and methods, which are different from the server interface, or else do not occur there.