ChainLink was presented by Sergey Nazarov and Ari Juels in 2017 with an ICO. It is a decentralized network of nodes that provides data and information from off-blockchain sources to on-blockchain smart contracts via oracles.

As it is well known smart contracts are predefined agreements on the blockchain that evaluate information and automatically execute actions when certain conditions are met. In this case, oracles play an extremely important role in facilitating the full potential of smart contracts utility as they act as a bridge between the real-world (off-chain) and on-chain smart contracts, by being a source of data that smart contracts can rely on, and act upon.

However, off-chain oracles tend to be centralized and that comes with a reliance on a third party to provide critical information in a trustworthy and time-critical manner. ChainLink aims to break this reliance by feeding information to smart contracts via a network of decentralized oracles that work together on the Link Blockchain to verify and forward critical information to these contracts.

LINK is an ERC20 token based on the Ethereum Blockchain. It serves as a payment to node operators for the retrieval of data from off-chain data feeds. Also, it has a maximum supply of 1 billion tokens, 35% of which were sold during the ICO.