Ark is massive !!!!
"The Ark protocol is built around the idea of shared UTXOs. In principle, Lightning also has shared UTXOs, however they are only shared between the two channel counterparties.
In Ark, UTXOs are shared among a large amount of users, potentially up to tens or hundreds of thousands of users.
While in the Lightning Network, payments are made by atomically shifting an amount of Bitcoin in a series of channels, in Ark, payments are made by exchanging a share in an existing shared UTXO for a share in a new shared UTXO. These shares of UTXOs will be called virtual UTXOs, or VTXOs.
These exchanges are coordinated by a central party, an Ark Service Provider (ASP), that facilitates payments, but is never a custodian.
Because the UTXO is shared among the users in the shared UTXO, they can claim back there
Bitcoin at all times without depending on the ASP by broadcasting their VTXO transactions."
