A style guide is a set of standards and guidelines for the visual and interactive design of a product. It outlines the look and feel of the product, and defines the design elements, such as typography, color, and layout, that should be used consistently across the product. In the context of product development, a style guide can help product teams create and maintain a cohesive and consistent user experience, and ensure that the design elements of the product are used consistently and correctly. A style guide can also serve as a reference for designers and developers, and provide a clear set of rules and guidelines for creating new design elements or making design decisions.