An endorsement policy specifies the organizations with peers that must properly approve or endorse a chaincode transaction before it's added to a block and submitted to the ledger. You can add an endorsement policy in OBP when you instantiate chaincode, which is step 2 in the chaincode deployment process. Endorsement guarantees the legitimacy of a transaction. If no endorsement policy is specified, then the default endorsement policy is used, which gets an endorsement from any peer on the network.

An organization's endorsing peer must have read-write permissions on the channel. When a transaction is processed, each endorsing peer returns a read-write set, then the client bundles these endorsing peers with their signatures and sends everything to the ordering service, which orders and commits the transactions into blocks and then to the ledger.

In the following screenshot, you can see the endorsement policy configuration while instantiating the chaincode. You can simply specify in the Signed by field how many have to participate in the endorsement, or by selecting Advanced, you can specify this through an expression too. In our use case, we are using the default endorsement policy: