We had a very informative talk from Jordan Bravo on how to use the Liquid sidechain. You can find his presentation notes here.

As a sidechain of Bitcoin, Liquid allows you to move bitcoin (BTC) between the Bitcoin mainchain and the Liquid sidechain through a verifiable 1-to-1 peg.

Bitcoin sidechains such as Liquid are blockchains that facilitate the transfer of assets to and from the Bitcoin mainchain via a two-way peg. The amount of BTC circulating on a sidechain is always verifiably equal to the amount of BTC “locked” on the Bitcoin mainchain.

While sidechains are interoperable with the Bitcoin mainchain, they operate independently of the Bitcoin network itself. Sidechains depend on Bitcoin; Bitcoin does not depend on sidechains.