Cardano is a decentralized blockchain platform launched in 2017 by Input Output Hong Kong (IOHK) under the leadership of Charles Hoskinson, a co-founder of Ethereum. It employs a proof-of-stake consensus mechanism called Ouroboros, designed to improve energy efficiency compared to proof-of-work systems. Cardano supports smart contracts and decentralized applications, with a focus on scalability, sustainability, and interoperability across blockchain networks.