the architecture of gRPC is layered: The lowest layer is the transport: gRPC uses HTTP/2 as its transport protocol. HTTP/2 provides the same basic semantics as HTTP 1.1 (the version with which nearly all developers are familiar), but aims to be more efficient and more secure. The new features in HTTP/2 that are most obvious at first glance are (1) that it can multiplex many parallel requests over the same network connection and (2) that it allows full-duplex bidirectional communication.