L-BTC is Bitcoin pegged into the Liquid Side Chain, either by individuals who ran Liquid Nodes or by federation members, L-BTC can only be created through this peg-in system and is destroyed through a peg out system that only federation members can do
Liquid is a fork of Bitcoin but doesn't use proof of work, instead a federation of block signers, so its by no means decentralised. I just use it temporarily so that I can stack sats cheap and then I swap out to the base chain when fees are reasonable