Understanding VO, DTO, DO, and PO: Concepts, Differences, and Practical Application in a Three‑Tier Architecture
This article explains the definitions of View Object (VO), Data Transfer Object (DTO), Domain Object (DO), and Persistent Object (PO), compares their roles, illustrates their placement in a three‑layer architecture, and provides guidance on when to merge or separate these objects in real‑world backend development.