LINK is the native utility token of Chainlink, a middleware oracle service. Chainlink was founded by Sergey Nazarov and Steve Ellis, who founded its parent company SmartContracts.com in 2014.
As a middleware service, Chainlink links smart contracts with real world data. Since blockchains are incapable of accessing data outside of their network, middelware services are necessary to feed reliable and tamper proof real-world data to them.
As of 2019, LINK was ranked 16th among cryptocurrencies by market capitalization.