Based on the way blockchain has evolved over the last few years, it can be divided into multiple types with distinct but sometimes partly overlapping attributes.
As the name suggests, these blockchains are open to the public and anyone can participate as a node in the decision-making process. Users may or may not be rewarded for their participation. These ledgers are not owned by anyone and are publicly open for anyone to participate in. All users of the permission-less ledger maintain a copy of the ledger on their local nodes and use a distributed consensus mechanism in order to reach a decision
about the eventual state of the ledger. These blockchains are also known as permission-less ledgers.
Private blockchains as the name implies are private and are open only to a consortium or group of individuals or organizations that has decided to share the ledger among themselves.
Here part of the blockchain is private and part of it is public. The private part is controlled by a group of individuals whereas the public part is open for participation by anyone.
More precisely known as pegged sidechains, this is a concept whereby coins can be moved from one blockchain to another and moved back. Common uses include the creation of new altcoins (alternative cryptocurrencies) whereby coins are burnt as a proof of adequate stake. There are two types of sidechain. The example provided above for burning coins is applicable to a one-way pegged sidechain. The second type is called a two-way pegged sidechain, which allows the movement of coins from the main chain to the sidechain and back to the main chain when required.
A permissioned ledger is a blockchain whereby the participants of the network are known and already trusted. Permissioned ledgers do not need to use a distributed consensus mechanism, instead an agreement protocol can be used to maintain a shared version of truth about the state of the records on the blockchain. There is also no requirement for a permissioned blockchain to be private as it can be a public blockchain but with regulated access control.
As the name suggests, this ledger is distributed among its participants and spread across multiple sites or organizations. This type can either be private or public. The key idea is that, unlike many other blockchains, the records are stored contiguously instead of sorted into blocks. This concept is used in Ripple.
This is generic term that is used to describe any application or database that is shared by the public or a consortium.
These blockchains perhaps have no mainstream application as they deviate from the core idea of decentralization in blockchain technology. Nonetheless in specific private settings within an organization there might be a need to share data and provide some level of guarantee of the authenticity of the data. These blockchains could be useful in that scenario. For example, for collaboration and sharing data between various government departments.
These blockchains are standard blockchains that generate cryptocurrency as a result of a consensus process via mining or via initial distribution.
These are probably not real blockchains because they lack the basic unit of transfer of value but are still valuable in situations where there is no need to transfer value between nodes and only sharing some data among various already trusted parties is required.
Follow me on :-
Youtube : https://goo.gl/2exULj
Instagram(Tech) : https://goo.gl/ikLTyb
Instagram(Food) : https://goo.gl/ht3bZM
Quora : https://goo.gl/sEoxY3
Medium : https://goo.gl/M3QvUq
Linekdin : https://goo.gl/LeaGSF
Steemit : https://goo.gl/o7RUj7
GitHub : https://goo.gl/3R38LK
Zomato : https://goo.gl/tMKpM5
