Read Bob Haegele explain what is Chainlink and why it is very important to the world of cryptocurrency on Yahoo Finance :
Blockchain has seen a staggering rise in popularity since Bitcoin, the first cryptocurrency, launched in 2010. Blockchain has a number of advantages, including decentralization and security. The demand for a decentralized currency has catapulted Bitcoin and other cryptocurrencies to worldwide popularity. But blockchain has its limitations. These systems are inherently closed off from the rest of the world, which is good for security and integrity but also limits the input data they can accept.
Read his full article here.
For more see : Chainlink.