## INTRODUCTION

Every blockchain application that handles value needs to answer the same question: how do you track who owns what? There are two dominant approaches, and choosing between them shapes your entire contract architecture.

Contract-state accounting behaves like a bank ledger. A single smart contract holds a balance map, and transactions update entries in place. The UTXO model behaves like physical cash. Each unit of value exists as an independent object that gets consumed and recreated with every transfer.

Midnight supports both patterns, and each has different tradeoffs for privacy, complexity, and scalability.…