Chainlink is a decentralized oracle network. It was created in 2017 to address the issue of smart contracts having to rely on external data sources to execute their terms, for example, on APIs. The project aims to incentivize a network of computers to provide reliable data that smart contracts need to run effectively on blockchains. LINK tokens are the digital asset token used to pay for services on the network.In essence, Chainlink allows data providers to act as bridges between blockchain smart contracts and external data sources in a decentralized way. It can connect price data, verifiable randomness, medical data, weather data, external APIs, and more to a blockchain.What are LINK's key features and how does it work?The data collected can be considered reliable as every oracle within the Chainlink network is given a reputation score, thus data providers are incentivized to provide accurate data to score highly. Chainlink has a three-step process in place to communicate with and collect this data from external sources.Oracle Selection. A service-level agreement is created to specify data requirements needed by users. The user is then matched to an oracle that can provide the specified data using the SLA. The user then submits the SLA and deposits LINK into an Order-Matching contract, which accepts bids from oracles to provide the data.Data Reporting. Data oracles connect with external data providers, collect the data, and then it is sent back through the smart contract on the Chainlink blockchain.Result Aggregation. Data collected by the oracles is analyzed by an aggregation contract. Results of the data oracle are scored and sent to the user.Chainlink’s architecture is fundamental to the way in which these processes work. It consists of three types of smart contracts:Aggregating Contracts collect data from oracles and match the results with the smart contract that is needed;Order-Matching Contracts match a service level agreement (SLA) with the best bidding oracles;Reputation Contracts verify oracle integrity. They check factors such as the total number of completed requests, average response time, and the amount of LINK cryptocurrency staked on the oracle. Chainlink is also able to communicate with independent oracles that do not operate directly on its blockchain. These nodes are made up of two components:  Chainlink Core is responsible for reading newly filed SLAs and sending data requests to the Chainlink Adapter.Chainlink Adapter acts as the bridge between the node and the external data. The adapter reads and processes data to then send it to the blockchain.Chainlink's technology is based on the hybrid consensus algorithms of Delegated Proof of Stake (DPoS) and Proof of Authority (PoA), to transport consistent data very quickly.