LINK is an ERC20 standardized token based on the Ethereum blockchain and is used to pay Chainlink node operators for retrieving data from off-chain data, formatting data into a blockchain-readable format, off-chain computing, and Guaranteed uptime. Chainlink tokens are used as part of running a node to protect against bad actors.

1. Project introduction

The first decentralized oracle network that allows anyone to securely provision smart contracts, access critical external data, offline payments and any other API functionality. Any user with a data feed, offline service (such as native payments), or any other API can provide it directly to a smart contract in exchange for LINK tokens.
The ChainLink network is a distributed network of ChainLink nodes, all of which directly feed specific data, APIs, and usage of various offline payment functions to smart contracts.
The Chainlink network consists of two separate parts, the on-chain and the off-chain, which must interact to provide services. This network is built in such a way that it can be upgraded, so its different components can be replaced as better technologies and technologies become available. The on-chain components of the network filter oracles through service-level agreements (SLAs) based on the metrics requested by a party to a smart contract. Using these metrics, Chainlink collects responses to SLA queries, ranks them using reputation and aggregation models, and provides final aggregated results for Chainlink queries that may be implemented into smart contracts.
The off-chain component of the network consists of oracle nodes connected to the Ethereum network that independently collect responses to off-chain requests. These off-chain nodes can be located in any industry, for example, the off-chain nodes operated by the New York Stock Exchange can provide real-time and accurate transaction information to the Chainlink network, or the Visa network off-chain nodes can resolve transactions with consumers and suppliers through the Chainlink network interact. Chainlink technology aims to integrate nodes from all these industries into a common network that itself acts as a (low-cost) middleman, interpreting and correctly distributing data as needed. The Chainlink system will ensure that results from oracles are accurate and allow oracles to remain independent of the data they provide.
Any data, payment, electronic signature or other API provider as well as individual developers can easily join the Chainlink network by connecting their familiar APIs to the network. Once an API is connected to ChainLink, the user becomes a ChainLink node operator and is responsible for connecting that API to the ChainLink network. To incentivize operators to provide API information, they are compensated in LINK tokens for successful completion of online linking requests.
This project currently provides a fully distributed oracle network compatible with Bitcoin, Ethereum and Hyperledger. Support for other blockchains is expected in the future, which will allow cross-chain connections between smart contracts and any other public or private chain, allowing anyone in the world to use the Chainlink network regardless of their platform. All service providers will be able to securely offer smart contracts to access critical external data and possibly even off-chain payments.

2. Comment

Chainlink (LINK) is a decentralized network that provides information (oracle) to smart contracts. Chainlink was founded in 2017 by Sergey Nazarov and Steve Ellis to solve the problem of off-chain information procurement through smart contracts for its execution parameters. Smart contracts are designed to execute automatically when certain parameters are met, however, when these parameters exist off-chain, they rely on sources of information (called oracles) to provide the necessary information. Off-chain oracles tend to be centralized and rely on third parties to provide critical information in a trustworthy and time-critical manner. ChainLink aims to break this dependency by feeding information to smart contracts through a decentralized network of oracles that work together on the Link blockchain to verify and forward key information to these contracts. The ChainLink network allows users with data feeds or information-bearing APIs to easily provide information to smart contracts in exchange for LINK tokens.
Chronicle of Events
September 2017 - ChainLink ICO.
November 2018 - Acquired Town Crier (smart contract and data privacy project).
June 13, 2019 - Announcing a partnership with Google
Utility
Link Network provides timely and accurate information to smart contracts through a decentralized network of oracles (data feeds and APIs) . This information is critical to the efficient and accurate execution of smart contracts, as the required information exists off-chain, and there must be a reliable way to obtain on-chain information. LINK tokens are used as payment for smart contracts that use data provided by the Link Network, where oracles that provide accurate information are rewarded in proportion to their share of LINK.
Key features
Partnerships with major industry players such as SWIFT and Google
Integration of Ethereum sidechains such as Harmony, Celer and Matic.
Average block time n/a; total supply 1 billion LINK; write Oracle Consensus to the Ethereum blockchain via threshold signatures.
Related links:
https://chain.link/
https://en.bitcoinwiki.org/wiki/ChainLink
https://everipedia.org /wiki/lang_en/chainlink-cryptocurrency
https://blog.chain.link/threshold-signatures-in-chainlink/
https://blockonomi.com/chainlink-guide/