Peers can be subdivided as follows:

• Mandatory peers: Endorsing peers, and non-endorsing peers, also known as committers and leader peers.
• Option peers: Anchor peers. These are optional, and a blockchain network can function and exist without them.

The following are the different types of peers available:

1. Endorsing peers: The preceding section covered endorsing peers in detail. Referring to the Architecture: conceptual view diagram, peers (P1 and P2) have chaincode installed by administrators of organizations (O1 and O2). Hence, they can endorse transactions, and are referred to as endorsing peers.
2. Non-endorsing peers (also known as committing peers): Referring to the preceding diagram, peer P4 (owned by organization O1) does not have chaincode installed. The administrator of organization 1 (O1) chose to install chaincode only on P1, and not on P4. This highlights two points: 
   • Firstly, organization administrators can selectively choose to install chaincode on peers.
   • Secondly, peers with chaincode installed are termed endorsing peers, and peers that do not have chaincode installed can exist on the channel. Such peers (P4) are non-endorsing peers (called committing peers). Every node on the channel is a committing peer:
     • Peers such as P4 (non-endorsing peers, also known as committing peers) cannot generate transactions. However, they can accept or reject transactions to ledger (L1).
   • Peers with chaincode installed can generate transactions and also endorse transactions.
   • Committing peers receive blocks of transactions (transactions initiated by endorsing peers) and are validated before being committed to a local copy of the ledger (L1). Such a commit to the ledger copy (L1) by the peers (endorsers and committers) constitutes an append-only operation to the ledger.

3. Leader peer: Organization O1 has two peers (P1 and P4) on the channel (C1), where P1 is an endorser and P4 is a committer. Hence, transactions need to be distributed to all peers (committers) in an organization (O1). The distribution of transactions means distributing from orderers to committing peers of the organization. To ensure a transaction distribution, a peer can be defined as a leader peer (statically), or any peer can assume the role of leader (dynamically). Hence, in our sample network, for Channel-C1 and organization O1, peer P1 is dynamically defined as the leader peer, which will distribute transactions to all peers of organization 1 (O1) that are attached to Channel-C1.
4. Anchor peer: For inter-organization, peer-to-peer communication, a channel requires an anchor peer. This is an optional peer and is only required when cross-organization communication is required.