Compared to Proof of work
(PoW) blockchains / cryptocurrencies like Bitcoin and Ethereum in its earlier version, which require a lot of electrical energy, Proof of Stake blockchains like Cardano do only require a minimal amount of electrical energy for running the servers which represent the network.
Holders of the Cardano cryptocurrency Ada can stake their funds to a staking pool like RENEW pool to get a yearly return on their investment of up to 4.x%.
Read more on Wikipedia about Cardano
, Proof of stake
, Proof of Work
and Decentralized finance