Bitcoin side chain. Developed by Blockstream. Liquid is pegged to BTC with a peg in/out process, verified on liquid blockchain. Chain is validated by a federation of 70+ institutions (check out Blockstreams stuff for more info, it's all open source) liquid has confidetial transactions and 1 minute block times. Jade HW wallet and Blockstream green are both compatible with liquid network as well. You can also issue assets on liquid and I believe is the prime candidate for el Salvadors volcano bonds. Also, tether is on liquid and I think this is a huge missed opportunity for LATAM as they continue to use shitcoin chains like tron and to send tether. Liquid is more confidential and secure. Not that I would advocate anyone use tether... I definitely don't. Just trying to hit all the main points.