Cardano is a public blockchain platform. It is open-source and decentralized, with consensus achieved using proof of stake. It can facilitate peer-to-peer transactions with its internal cryptocurrency, Ada.
Cardano was founded in 2015 by Ethereum co-founder Charles Hoskinson. The development of the project is overseen and supervised by the Cardano Foundation based in Zug, Switzerland. It is also the most prominent cryptocurrency used as a proof-of-stake blockchain, providing a greener alternative to proof-of-work protocols.

Typically, Cardano does not have a white paper. Instead, it uses design principles intended to overcome issues faced by other cryptocurrencies. Cardano addresses characteristics such as scalability, interoperability, and regulatory compliance.

Cardano uses a proof-of-stake protocol named Ouroboros; this is in contrast to Bitcoin and Ethereum, which use proof-of-work protocols. Proof-of-stake blockchains use significantly less energy than proof-of-work chains.

Within the Cardano platform, Ada exists on the settlement layer. This layer is similar to Bitcoin and keeps track of transactions. The second layer is the computation layer, designed to be similar to Ethereum, enabling smart contracts and applications to run on the platform.

Cardano expects to implement decentralized finance (DeFi) services on September 12, 2021. These services will include an upgrade to enable smart contracts and build decentralized applications (DApps). Also included is Plutus, a Turing-complete smart contract language written in Haskell, and a specialized smart contract language, Marlowe, designed for non-programmers in the financial sector. Cardano’s smart contract languages allow developers to run end-to-end tests on their program without leaving the integrated development environment or deploying their code.

Holders of Cardano can stake their Ada to receive interest on their investment through so-called epoch payments.