What is blockchain? A blockchain is a type of Digital Ledger Technology (DLT) that consists of growing list of records, called blocks, that are securely linked together using cryptography. One of the applications of blockchain is the Bitcoin

History of blockchain

A blockchain was created by a person (or group of people) using the name (or pseudonym) Satoshi Nakamoto in 2008 to serve as the public distributed ledger for bitcoin cryptocurrency transactions, based on previous work by Stuart Haber, W. Scott Stornetta, and Dave Bayer.

CHARACTERISTICS

*Immutable. Immutability means that the blockchain is a permanent and unalterable network. ...

*Distributed. All network participants have a copy of the ledger for complete transparency.

*Decentralized

*Secure

*Consensus

TYPES

Public Blockchain

Private Blockchain.

Consortium Blockchain

What is consensus mechanism and what are the popular types?

The consensus mechanism is extremely important to the blockchain network because it is used to reach agreement especially since it’s decentralized It influences how transactions are verified, how much energy is used, network fees, transaction speed

Types

Proof of work(PoW) used in Bitcoin

Proof of stake (PoS) eutherum

Proof of Authority (PoA) etc

What is a blockchain Layer 1 vs. Layer 2?

The term Layer 1 refers to the base level of a blockchain architecture. It’s the main structure of a blockchain network. Bitcoin, Ethereum, and BNB Chain are examples of Layer 1 blockchains.

Layer 2 refers to networks built on top of other blockchains. So if Bitcoin is a Layer 1, the Lightning Network that runs on top of it is an example of a Layer 2

Why was layer 2 needed?

Layer 2 solutions are important because they allow for scalability and increased throughput while still holding the integrity of the Ethereum blockchain.

What are smart contract?

Smart contracts are digital contracts stored on a blockchain that are automatically executed when predetermined terms and conditions are met.

Characteristics/ benefits

– Transparency. The participants have the same information at the same time, which minimises possible manipulations of the clauses of the contract

– Cost reduction.

• Speed.

  – Permissionless

• immutable

• Dertermistic

Languages of smart contract

+solidity

+vyper

+yul

+rust

What is a decentralized finance?

Decentralized finance (or "DeFi") is a financial ecosystem based on blockchain technology. It lets users buy and sell assets and financial services as a form of investment or financing without middlemen.

Benefits of DeFi

•DeFi is permissionless and inclusive.

•Transactions are in real time. The underlying blockchain is updated the moment a transaction is completed, and interest rates are updated multiple times every minute.

•Transactions are transparent.

•Smart contracts are highly programmable and can be designed to automatically execute, based on an infinite number of variables.

•DeFi data is tamper proof, secure and auditable, thanks to the use of blockchain architecture.

•Many DeFi protocols are open source.