What are ruler guides used for in a digital document?

Ruler guides serve a critical function in digital document design by providing visual references for aligning objects. When designing, accuracy and consistency in layout are vital, and ruler guides help achieve that by allowing designers to place objects—such as text boxes, images, or shapes—at precise locations relative to one another and the edges of the document. This facilitates the creation of a polished, professional-looking layout.

In contrast, the other options pertain to different functionalities within digital design software. Creating layers automatically does not involve the use of ruler guides; instead, layers are a separate organizational feature used to manage different elements of a design. Adjusting color settings is a distinct aspect of document formatting that deals with color management, not object alignment. Finally, saving the document layout relates to the overall document storage process, which is not directly connected to the use of ruler guides for alignment purposes.