Ethereum is been founded in 2014, it's the world's programmable blockchain, so you can also use it for lots of different digital assets, It's also a open marketplace of financial services, games and apps. The Ethereum network uses POW (Proof of consensus), the huge number of miners give protection to the network.
Zilliqa's white-paper is been created in 2017, it is another blockchain project which as similar as Ethereum, but with some unique features such as sharding and high TPS (Transactions per second). Zilliqa use different consensus method, including both POS (Proof of Stake) and POW.