How decentralized is Cardano?
Cardano is arguably one of the most decentralized proof of stake cryptocurrencies, with around 3000 staking pools. These are run either by single pool operators or operators running multiple pools.
How much energy does Cardano consume to secure the blockchain?
The proof of stake method of Cardano is energy-efficient compared to other blockchain technologies. In a blog post by IOHK (development company for Cardano) they estimate that the energy usage is 0.01% of Bitcoin.
Is there a hard limit on the total number of ADA?
Yes, Cardano has a hard limit of 45,000,000,000 ADA for maximum supply.
What are epochs and slots in Cardano?
Epochs lasts for 5 days in the Ouroboros-protocol, which Cardano uses to secure the network. Slots happen every 1 second but on average, a block updating transactions on the Cardano blockchain happens every 20 seconds.