What is BlockChain?

“BlockChain is Technology behind BitCoin System”

The blockchain is a chain of blocks where each block contains data of value. It is cryptographically secure and immutable. Every block has there owned address or Hash key which is unique (SHA256).

SHA256- SHA256 is Digital Hash key which contains 64 characters.

“Blockchain is a book that is continuously growing list of records called blocks which are linked and secured using cryptography.”


Genesis block :

Genesis block is the first block of Blockchain, generated by the originator of the blockchain.
Every block in blockchain traces back to the genesis block and is the only block which is not linked to any previous block.

A node in Blockchain:

A node is a device that connects to blockchain Network. Any type of device that has internet can act as a node.

There are multiple nodes in one Blockchain network.

Decentralization in BlockChain:

Decentralization means transferring authority from the centralization system to each local system.
In centralization system, if central authority goes rogue. Then he can damage the entire system.
In Blockchain, when you make any transaction, it‘s done completely without central authority verifying your transaction, miners keep their own copy of ledger and verify transaction using their own ledger.
Every transaction in blockchain is verified by multiple miners before it goes into blockchain permanently. No central authority required, even if one miner goes rogue it won’t affect other miners present in the network or even the network itself.
Blockchain uses private key Cryptography to secure identities and Hash functions to make the blockchain immutable.
The blockchain is a Concept and can be Implemented by any Language.
Solidity is a most preferred default for writing programs in Blockchain, Solidity is the Contract-oriented Programming language for Writing a smart contract.
Solidity was initially proposed in Aug 2014.

BlockChain Type :

  1. Public: In a public Blockchain, Anyone can transact in the Network. Anyone can access and read transactions. Transaction are transparent.   (In Network Every one can verify, view and add Block)
  2. Private: In a private Blockchain, write permission kept centralized into one organization. Read permission could be public or restricted to any degree. (only specific people verify and add block but can view all.)
  3. Consortium: In a consortium network. The power does not reside with a single authority. It is operated under the leadership of a group. (only a group or organization can verify and add block, but the ledger can open and or restricted to a selected group.)

We can use at a time one or More than one Blockchain Type.

The more popular blockchain / distributed ledger systems.

  • BigChainDB
  • Chain Core
  • Corda
  • Credits
  • Elements Blockchain Platform
  • Eris: DB
  • Ethereum
  • HydraChain
  • Hyperledger(Fabric, Iroha, Sawtooth, Burrow, Indy )
  • Multichain
  • Open-chain
  • Quorum 

Blockchain use case:

  • Banking
  • Payment & Transfer
  • Health Care
  • Law enforcement
  • Voting
  • IOT
  • Online music
  • Real Estate