Casper is the Ethereum consensus mechanism that will transform the Ethereum network, which was previously known as the Ethereum Execution Layer (previously Ethereum 1.0), into a proof-of-stake (PoS) system called the Ethereum Consensus Layer (previously Ethereum 2.0). Casper will be released as part of Ethereum’s Beacon Chain and will include several upgrades. Casper has been co-developed with two main Ethereum implementations as of March 2021, Casper CBC (Correct by Construction) and Casper FFG (Friendly Finality Gadget).