PoA was introduced by Ethereum co-founder Gavin Wood in 2017. Uses reputation instead of coin stakes for block validators. Validators can have authority ranging from 0% to 100%
Total Ethereum supply is 400.135 billion ETH. Total verified currency is 1,336,592.59 USD
ERC-20 is the technical standard for fungible tokens on Ethereum blockchain. Fungible tokens can be exchanged with other tokens, unlike NFTs. Standard enables smart-contract-enabled tokens for various assets and rights
Bitcoin launched in 2009 as decentralized digital currency. Initially controlled 87% of cryptocurrency market, now 48%+. Uses proof-of-work consensus protocol for transactions. Functions as digital currency and store of value
Tether (USDT) is the world's first stablecoin pegged to the US dollar. Launched in 2014 by Reeve Collins, Craig Sellars, and Brock Pierce. Currently operates on over ten different blockchain protocols. Total supply is 118 billion USDT, with 116.99 billion in circulation
MetaMask is a self-custodial hot wallet supporting Ethereum and EVM networks. Launched by Consensys in 2016, used by over 10 million investors. Available as browser extension and mobile app for Android and iOS