Founded in September 2017 by Ethereum co-founder Charles Hoskinson, Cardano is one of the largest active blockchains to successfully use a Proof-of-stake consensus mechanism. ADA is the proof-of-stake coin native to the Cardano blockchain that fuels transactions and smart contract operations on the network. Asides addressing scalability issues with their Ouroboros proof-of-stake system, Cardano also aims to improve interoperability issues throughout other cryptocurrency platforms by utilizing sidechain protocols that will enable the Cardano blockchain to understand what’s happening in other blockchains. The maximum supply of ADA that will ever exist is capped at 45 Billion. 


More information here https://cardano.org/