The blockchain architecture gives participants the ability to share a ledger that’s updated
through peer-to-peer replication each time a transaction occurs.
Peer-to-peer replication means that each participant (also called a node) in the network acts as both a publisher and a subscriber.
Each node can receive or send transactions to other nodes, and the data is synchronized across the network as it’s transferred. The blockchain network is economical and efficient because it
eliminates duplication of effort and reduces the need for intermediaries. It’s also less vulnerable because it uses consensus models to validate information. Transactions are secure, authenticated,
and verifiable. The participants in both transaction systems are the same. What has changed is that the transaction record is now shared and available to all parties.
A blockchain network has the following key characteristics:
- Consensus: For a transaction to be valid, all participants must agree on its validity.
- Provenance: Participants know where the asset came from and how the ownership has changed over time.
- Immutability: No participant can tamper with a transaction after it has been recorded to the ledger. If a transaction is in error, a new transaction must be used to reverse the error and both transactions are then visible.
- Finality: A single, shared ledger provides one place to go to determine the ownership of an asset or the completion of a transaction.
Source: Blockchain for Dummies