Transformation functions manipulate objects between coordinate spaces by applying transformations. Transformation functions require two coordinate spaces: a source coordinate space, and a target coordinate space. Which transformation function an application should use is determined by the two coordinate spaces and by the transformation effect desired.

The world-to-model space, model-to-page space, and page-to-device space transformations are all actually performed as a single operation. The different coordinate spaces are conceptual in nature, rather than explicitly defined entities. Describing them separately is meant to help explain the levels of activity during transformations.

All transformation functions share certain parameters, although the values and defaults of those parameters might not be identical.