What is eUTXO and how does it work?

eUTXO (Extended Unspent Transaction Output) is Ergo's smart contract model that extends Bitcoin's UTXO with programmable logic. Each 'box' contains ERG, tokens, data registers, and a guarding script. Transactions consume boxes and create new ones, enabling deterministic execution, parallel processing, and no protocol-level reentrancy by construction.

• Boxes = UTXOs with superpowers: value + tokens + data + script
• Deterministic: execution cost known before sending
• Parallel: unrelated transactions process simultaneously
• Secure: no reentrancy, no front-running by design