What is a gRPC channel?

A gRPC channel is a connection abstraction representing a virtual connection to a gRPC server endpoint. It encapsulates the HTTP/2 connection(s) to the server and manages connection lifecycle, reconnection, load balancing, and channel state. You create a channel with the server address: channel = grpc.insecure_channel('localhost:50051') (Python) or conn, _ := grpc.Dial('localhost:50051', grpc.WithInsecure()) (Go). The channel is lazy — it doesn't connect immediately but on the first RPC call. A channel goes through states: IDLE, CONNECTING, READY, TRANSIENT_FAILURE, SHUTDOWN. You create stubs from a channel: stub = ProductServiceStub(channel). Channels are expensive to create (TCP handshake, TLS negotiation, HTTP/2 setup), so they should be long-lived and reused across multiple calls, not created per request.