Thank you @stream4u for this simple and amazing lecture. It was beautiful researching this topic. I answered the 3rd question *** >What Is Public Chain and What will be the Advantages and Disadvantages of Public Chain? ###

What Is Public Chain

![image.png](https://cdn.steemitimages.com/DQmT1BnrZbAbMxdcZtqSGf1mKrNfTFpqFDMo1cALmZEPvFo/image.png) A public chain is a decentralized platform that is open and accessible to the public. There are basically no restrictions and anyone with an internet connection can have access to the network and begin validating and sending transactions. There usually are incentives for users who validate these blocks. A Public chain tends to use Proof-of-Work and Proof-of-Stake consensus algorithms in validating transactions. No one has control over it and it supersedes the necessity of an intermediary. It is self-governing, totally decentralized, and autonomous. It operates in a very simple manner. The public blockchain protocol can be downloaded by anyone and permission is not required from anyone. It is an ideal model that makes the tech industry very profitable. *** ####

Characteristics of public blockchain

* Nodes can be downloaded and added to the system by anyone * It is a fully decentralized technology * There is privacy and it offers anonymity, meaning that transactions cannot be tracked. * It is relatively slow when compared to private blockchain * Every node has read and write access on the ledger. *** ####

Examples of public chain

Bitcoin, Ethereum, and Litecoin are popular examples of public blockchain with Ethereum being the most popular and taking the concept to a whole new level. *** ####

Advantages of public chain

* **Greater Transparency** A public chain provides more transparency as compared to private networks and is more decentralized because anybody may join and no single entity has authority over the entire system. * **Truly decentralized structure** The network is highly decentralized and all the nodes in the system have their own copy of the ledger using various consensus algorithms. It truly has no need for a central authority. * **User empowerment** it has good user involvement as anyone with access to the internet can download a copy of the chain and read or rewrite it with complete authority. this simply means that the control panel is in the hands of the general public, not a wicked company. * **Immutability** The public network cannot be tampered with or have money stolen from it because it is completely immutable. If a user ever attempts to tamper with the blocks such as double-spending, the nodes will reject the transaction hence fraud and other problems can be controlled using this technology. * **Security** Highly secure for decentralization and higher nodes. Data is secured and cannot be modified or altered once they have been validated and stored in the blockchain network *** ####

Disadvantages of public chain

* Slow Transactions speed * Low Scalability * High Energy consumption during mining * Lack of regulation can cause it to be used for illegal activities *** ####

Conclusion

A public chain is a decentralized platform that is open and accessible to the public and very simple to operate. It is very secure and transparent but has a slow transaction speed amongst others. There are different examples of public chain but Ethereum stands out to be the most popular. cc: @stream4u