Bitcoin Sidechain: Lightning Network
A sidechain is a blockchain that runs parallel to the Bitcoin blockchain, enabling the deployment of new features and capabilities while leveraging bitcoin’s security. A sidechain is interoperable with the Bitcoin blockchain and supports the secure transfer of assets between chains. The company called BLOCKSTREAM a vital contributor to the development of the Bitcoin Lightning Network via development of the side chain, which was/is the backbone of the Lightening Network. Lightning Network, an open network is built on top of Bitcoin to enable fast, cheap and private microtransactions.
This features is to cryptocurrency what micro loans are to third world nations. It allows small economies to exist, which enriches small business operations.
The best example of Steemit is Steem Engine.