User Guide: SDKs > VoltMX Iris SDK > Invoking an Object Service > Data Transfer Objects

Data Transfer Objects

A data transfer object (DTO) represents a database element in a programmatic context. Each DTO is used in various Object Services API methods. However, DTOs are used only for offline Object Services, not for online Object Services. The DTOs comprise several classes:

• voltmx.sdk.dto.Column Class
• voltmx.sdk.dto.DataObject Class