1. What is Public Blockchain ? 
Public blockchains R open ne2rks that allow any1 2 participate in the ne2rk i.e. public blockchain is permissionless. In this type of blockchain any1 can join the ne2rk & read, write, or participate within the blockchain. A public blockchain is decentralized & does not have a single entity which controls the ne2rk. Data on a public blockchain R secure as it is not possible 2 modify or alter data 1ce they have been validated on the blockchain. 

Some features of public blockchain R : 
 High Security – It is secure Due 2 Mining (51% rule). 
 Open Environment – The public blockchain is open 4 all. 
 Anonymous Nature – In public blockchain every 1 is anonymous. There is no need 2 use yur real name, or real identity, therefore everything would stay hidden, & no 1 can track U based on that. 
 No Regulations – Public blockchain doesn’t have any regulations that the nodes have 2 follow. So, there is no limit 2 how 1 can use this platform 4 their betterment 
 Full Transparency – Public blockchain allow U 2 see the ledger anytime U want. There is no scope 4 any corruption or any discrepancies & every1 hs 2 maintain the ledger & participate in consensus. 
 tru Decentralization – In this type of blockchain, there isn’t a centralized entity. Thus, the responsibility of maintaining the ne2rk is solely on the nodes. They R updating the ledger, & it promotes fairness with help from a consensus algorithm . 
 Full User Empowerment – Typically, in any ne2rk user hs 2 follow a lot of rules & regulations. In many cases, the rules might not even be a fair 1. But not in public blockchain ne2rks. Here, all of the users R empowered as there is no central authority 2 look over their every move. 
 Immutable – When something is written 2 the blockchain, it can not be changed. 
 Distributed – The database is not centralized like in a client-server approach, & all nodes in the blockchain participate in the transaction validation.  

2. What is Private Blockchain ? 
A private blockchain is managed by a network administrator and participants need consent to join the network i.e., a private blockchain is a permissioned blockchain. There are one or more entities which control the network and this leads to reliance on third-parties to transact. In this type of blockchain only entity participating in the transaction have knowledge about the transaction performed whereas others will not able to access it i.e. transactions are private. 

Some of the features of private blockchain are : 

17Full Privacy – It focus on privacy concerns. 
 Private Blockchain are more centralized. 
 High Efficiency and Faster Transactions – When you distribute the nodes locally, but also have much less nodes to participate in the ledger, the performance is faster. 
 Better Scalability – Being able to add nodes and services on demand can provide a great advantage to the enterprise.