In this section, we will look at the architecture of blockchain, how it works, and what the salient features are that make it so disruptive. Blockchain was created by Satoshi Nakamoto as an infrastructure for Bitcoin and it is treated as the biggest thing since the internet. Blockchain, at a high level, consists of three major components, which are shown in the following diagram:

Let's now look into the following three major components of blockchain: 

• P2P Network: A peer-to-peer network (P2P) helps maintain a consistent copy of the distributed ledger. All the transactions that are captured on the blockchain in the form of blocks are maintained across the network of nodes running the blocks and programs by the distributed ledger.
• Private Key Cryptography: This component is used by blockchain for the security and hash functions that make it immutable.
• Blockchain Program: This component is used by blockchain as a protocol to execute steps that make it secure.