First let me tell you that there are 3 kinds of nodes:
- Orderer service node
Clients are nodes that submit transactions to endorsers and broadcast transaction proposals to ordering service.
Peers are the nodes that commits transactions and maintains the state and copy of ledger.
Ordering service nodes are nodes that run communication services and guarantees delivery.
Irrespective of the kind of nodes, the nodes communicate with each other using the gRPC protocol.