2Defination :

We know there are many tecnologies develope today in which we are eager to make our carrer,one of the hot technology in all of them is a “Blockchain”.

A blockchain is essentially a digital ledger of transactions that is duplicated and distributed across the entire network of computer systems on the blockchain.

A digital ledger means if over a chain of blocks contaiing a transactions ,if any attacker try to make changes in transactions or try to tempered the transactions , this change cause a change in hash of that particular transaction and this change reflected in the change in block hash ,due to which there is chances of breaking chain .,but as it is a digital ledger and due to it’s distributed property all the nodes get to know the respective tempering over a blockchain network and attacker gets detected .


1Types Of Blockchian

Public Blockchain

A public blockchain is a blockchain that anyone in the world can read, send transactions too and expect to see them included if they are valid, and anyone can participate in the consensus process – the process for determining what blocks get added to the chain and what the current stat is.

In case of public blockchain ,everyone operating over a blockchain network,come to know the transactions happening and everyone in a network are able to see the transactions. 

Public blockchains are secured by cryptoeconomics – the combination of economic incentives and cryptographic verification using mechanisms such as proof of work (Bitcoin) or proof of stake (Ethereum). These blockchains are generally considered to be “fully decentralized.” One of the drawbacks is the substantial amount of computational power necessary to maintain a distributed ledger at a large scale.


Consensus is a type of argument ove r a blockchain network that shoul be satisfied.

Private Blockchain

A fully private blockchain is a blockchain where write permissions are kept to one organization. Read permissions may be public or restricted to certain participants.

Consortuim Blockchain

A consortium blockchain is a blockchain where the consensus process is controlled by a pre-selected set of nodes, for example, a consortium of 15 financial institutions, each of which operates a node and of which 10 must sign every block in order for the block to be valid.

The right to read the blockchain may be public, or restricted to the participants. Some examples of consortium blockchains include R3 (banks) and EWF (Energy). Consortium blockchains are also referred to as federated blockchains.

Blockchain info : https://dragonchain.com/blog/differences-between-public-private-blockchains