Chainlink is a full spectrum web3 service provider. LINK is the first oracle in the blockchain space. Essentially it serves as a bridge between traditional data storage servers and blockchain protocols. While blockchains are advantageous for certain data types they will never fully replace all storage mechanisms. Link provides a method of communication between off-chain data and on-chain data. This might include commodity prices, or gps tracking information, even real time sporting game statistics, and many other sources.
LINK is used by the chainlink network to reward node operators. These are computers or servers that receive the off-chain data and package it so that it may be read by the hybrid smart contracts that interact with the blockchains. There is a fixed supply of LINK of 1 billion tokens; a little more than half of these are released into circulation.
We believe that the service that LINK provides is immeasurably valuable and will become increasingly demanded. Since LINK is the financial incentive for node operators, the value of LINK is well positioned to appreciate. You may learn more at CoinMarketCap.