Blockchain technology is a network of peer-to-peer nodes that keeps transactional records, also known as blocks, of the public in various databases, also known as the "chain." The notion or protocol that underpins the blockchain's operation is known as blockchain technology. Cryptocurrencies (digital currencies secured by cryptography) such as Bitcoin are made possible by blockchain technology, much as email is made possible by the internet.

Two essential blockchain properties are immutability and distributed. Because the ledger is immutable, you can always rely on it to be correct. The blockchain's decentralised nature protects it against network threats. On the ledger, each transaction or record is stored in a "block." Blocks on the Bitcoin blockchain, for example, typically contain more than 500 Bitcoin transactions. A block's information is dependent on and related to the information in previous blocks, forming a chain of transactions across time. Mining is the process of adding transactional details to the current digital/public ledger in Blockchain technology. Though it is most commonly connected with Bitcoin, the phrase is also applied to other Blockchain technologies. Mining entails creating a difficult-to-forge hash of a block transaction, maintaining the security of the entire Blockchain without the need for a central mechanism. There are following four types of blockchain technology,

Public Blockchain-

Anyone who wants to request or validate a transaction can use public blockchains, which are open, decentralized networks of computers (check for accuracy). Those who validate transactions (miners) get rewarded. Proof-of-work or proof-of-stake consensus procedures are used in public blockchains. The Bitcoin and Ethereum (ETH) blockchains are two popular instances of public blockchains.

Private Blockchain-

Private blockchains aren't public, and access is restricted. The system administrator must give permission to everybody who wants to join. They are usually centralized and managed by a single entity. Hyperledger, for example, is a permissioned, private blockchain.

Hybrid Blockchain or Consortiums-

Consortiums are a hybrid of public and private blockchains with both centralized and decentralized functionality. Energy Web Foundation, Dragonchain, and R3 are just a few examples.

Sidechains-

A sidechain is a blockchain that runs in the opposite direction of the main chain. It improves scalability and efficiency by allowing users to move digital assets between two separate blockchains. The Liquid Network is an example of a sidechain.

Blockchain is a combination of three leading technologies:

• Cryptographic keys
• A peer-to-peer network containing a shared ledger
• A means of computing, to store the transactions and records of the network

Cryptographic Keys-

Two keys are used in cryptography: a private key and a public key. These keys aid in the effective completion of transactions between two parties. These two keys are unique to each person and are used to create a secure digital identity reference. The most significant component of Blockchain technology is the secure identity.

Process of blockchain:

The way Blockchain technology confirms and authorises transactions is one of its most important aspects. For example, if two people want to make a transaction using their private and public keys, the first person would attach the transaction information to the second person's public key. This entire set of data is compiled into a block. A digital signature, timestamp, and other crucial, relevant information are all included in the block. It's worth noting that the block doesn't contain the identities of the people involved in the transaction. This block is then sent across all of the network's nodes, and the transaction is completed successfully when the proper person uses his private key to match it with the block.