Styles are a powerful option to use wherever one wants to control color, appearance, or content via Form Fields or logic. Basically, every aspect of a frame can be controlled with Styles. Since one frame can use several Styles, you can solve pretty complex problems with them.
Another good use for Styles are documents where you or the Buyer would like to change the appearance of several frames at once. Each frame can have one or more Styles applied.
As Styles and Form Fields are used together to create beautiful personalized products, please take a moment to check out their respective User Manual resources in the links below: