A blockchain is, in the simplest of terms, a time-stamped series of immutable records of data that is managed by a cluster of computers not owned by any single entity. Each of these blocks of data (i.e. block) is secured and bound to each other using cryptographic principles (i.e. chain). So, what is so special about it and why are we saying that it has industry-disrupting capabilities? The blockchain network has no central authority — it is the very definition of a democratized system. Since it is a shared and immutable ledger, the information in it is open for anyone and everyone to see. Hence, anything that is built on the blockchain is by its very nature transparent and everyone involved is accountable for their actions.

1. - By Prayank Verma

2. Structure of presentation
 What is blockchain?
 How blockchain works ?
 Blockchain Architecture
 Why do we need Blockchain?
 Evolution of Blockchain
 Blockchain Use Cases
 Limitation
 Conclusion

3. What is blockchain?
 Blockchain can be defined as a chain of the block
that contains information ,which are linked using
cryptography.
 The blockchain is used for the secure transfer of
items like money, property, contracts, etc. without
requiring a third-party intermediary like bank or
government. Once a data is recorded inside a
blockchain, it is very difficult to change It.
 The first blockchain was created by Satoshi
Nakamoto in 2008

4. How blockchain works ?

5. Blockchain Architecture

6. Blockchain Architecture

7. Why do we need Blockchain?
 Security: With the help of Distributed Ledger Technology,
each party holds a copy of the original chain, so the system
remains operative, even the large number of other nodes fall.
 Transparency: Changes to public blockchains are publicly
viewable to everyone.
 Decentralized: There are standards rules on how every node
exchanges the blockchain information.
 Fraud Prevention: The concepts of shared information and
consensus prevent possible losses due to fraud
 Reliability: Blockchain certifies and verifies the identities of
the interested parties. This removes double records, reducing
rates and accelerates transactions.

8. Evolution of Blockchain
1st generation: Store and transfer of value (e.g. Bitcoin, Ripple,
Dash)
2nd generation: Programmable via smart contracts (E.g.
Ethereum)
3rd generation: Enterprise blockchains (E.g. Hyperledger,
R3 Corda & Ethereum Quorum)
Next Generntion: Highly scalable with high concurrency (E.g.
RChain)

9. Blockchain Use Cases

10. Blockchain Variants
 Public:
In this type of blockchains, ledgers are visible to everyone on the
internet. It allows anyone to verify and add a block of
transactions to the blockchain.Anyone can use a public
blockchain network.
 Private:
The private blockchain is within a single organization. It allows
only specific people of the organization to verify and add
transaction blocks. However, everyone on the internet is
generally allowed to view.

11. Limitations
Higher costs
Slower transactions
Risk of error
Transaction costs

12. Conclusion
 A Blockchain is a chain of blocks that contain
information
 The blockchain is not Bitcoin, but it is the technology
behind Bitcoin
 Every block contains hash.
 Each block has a hash of the previous block
 Blockchain require Proof of Work before a new block
is added
 The blockchain database is disturbed amongst
multiple peers and is not centralized.