greatbody
/
freeCodeCamp
mirror of https://github.com/freeCodeCamp/freeCodeCamp.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Added the Types of Blockchains section (#24242) 

Briefly described permissionless and permissioned blockchains
pull/24354/head^2
arun-sharma-blr 2018-12-09 08:06:49 +05:30 committed by Manish Giri
parent 5f1a596cc1
commit e9fc27ad8f
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
guide/english/blockchain/index.md
View File

@ -28,11 +28,19 @@ The words block and chain were used separately in Satoshi Nakamoto's original pa
As of 2016, blockchain 2.0 implementations continue to require an off-chain oracle to access any "external data or events based on time or market conditions to interact with the blockchain."
### Types of Blockchains
Blockchains can be broadly classified into two categories -
1. Permissionless, public blockchains - these are not controlled by any single company or person. The blockchain is accessible to anyone to participate in. Bitcoin and Ethereum are examples of permissionless blockchains. Consensus is arrived at by participating miner nodes in the network, who perform certain actions (Proof-of-Work) and are rewarded for helping to maintain the state of the distributed ledger. Anyone interested can become a miner and participate in the consensus building process.
2. Permissioned blockchain - these are typically owned by a single party, or by a consortium of organizations. The participants in the network, along with their roles in the network, are pre-determined. These kinds of blockchains are implemented by enterprises who are looking to improve efficiencies across business processes that span multiple parties. Examples of permissioned blockchain platforms would be Ripple, Corda, Quorum and Hyperledger. [Hyperledger](https://www.hyperledger.org) is an open source project run by [The Linux Foundation](https://www.linuxfoundation.org/projects/), and is a set of frameworks and tools which can be used to build permissioned blockchain networks. Of the frameworks available, Hyperledge Fabric has gained a level of maturity required for production level blockchains.
### Bitcoin
Bitcoin’s main problem to solve was to achieve distributed consensus while remaining a decentralized system. Distributed consensus is essentially the idea that all the nodes that make up the network must come to a collective agreement without the use of a centralized control. In Bitcoin, the nodes are agreeing on exactly which transactions present on the network are valid. This is difficult in many ways, one of which is the potential for n number of nodes to be malicious and not want to follow
the consensus of the other nodes. Bitcoin has the benefit of being able to incentivize its nodes to “follow the rules” through rewards and transaction fees because it is a currency system.
#### Sources
1. [Bettina Warburg, "How the blockchain will radically transform the economy", *TED Talks*, December 8, 2016](https://youtu.be/RplnSVTzvnU?t=213)
2. [Depository Trust and Clearing Corporation, "Embracing Disruption: Tapping the Potential of Distributed Ledgers to Improve the Post-Trade Landscape", DTCC, 2016]