eUTXO vs Accounts vs Classic UTXO

This graphic compares three major blockchain state models: classic UTXO as used by Bitcoin, the global account model common on many smart-contract platforms, and Ergo's eUTXO design.

The top row shows how each model represents state. Classic UTXO is built around simple input and output boxes — ideal for payments, but limited for rich on-chain logic. The account model uses a shared global state where many users and contracts read and write the same balances and storage, creating conflict risks when transactions collide. eUTXO, as implemented on Ergo, treats each box as a self-contained state plus script, so transactions consume and create boxes that behave like local state machines.

The lower table compares the three approaches on parallelism and conflicts, logic transparency, smart-contract friendliness and fee/gas predictability — showing where each model shines and where it creates complexity for builders and users.