in the context of cashu, its a token that gives you permission to move sats in a lightning channel someone else controls, assuming they keep the server running for the duration you hold the token, and if they have enough liquidity to move it. The token itself has nothing to do with bitcoin. custodial lightning isn’t much better, but it less software and less complex. non-custodial lightning is much more fun. you don’t have to worry about people rugging you or randomly disappearing with your money one day. I can’t imagine running my business on someone elses node.