gRPC over HTTP/2 is generally faster than REST over HTTP/2, and the reasons come down to how each is designed. gRPC uses Protocol Buffers (protobuf), which is a compact and efficient binary format, unlike REST, which typically relies on JSON—a text-based format that's slower to process and takes up more space. Another advantage of gRPC is its built-in support for bidirectional streaming, allowing the client and server to send data back and forth in real-time. REST, on the other hand, sticks to the traditional request-response model, which isn’t as efficient for streaming. While both gRPC and REST benefit from HTTP/2 features like multiplexing and header compression, gRPC is designed to make the most of these features, resulting in lower latency and better performance, especially in high-throughput scenarios.