Explanation: A style guide is a document that defines the visual identity and branding of a company, such as the logo, color palette, typography, iconography, imagery, and tone of voice. It helps ensure consistency and coherence across different platforms and channels, and communicates the company’s values and personality. When implementing a company’s brand on Salesforce, the style guide should be the source of truth for consistency, as it provides the guidelines and rules for applying the brand elements to the user interface. A style guide can also include a pattern library, which is a collection of reusable UI components and design patterns that follow the style guide. A design principle is a statement that expresses the core values and goals of a design process, and guides the decision making and evaluation of a design solution. The Salesforce Lightning Design System (SLDS) is a set of design guidelines and resources for creating consistent and beautiful user experiences on the Salesforce platform. It can be used as a reference and a foundation for customizing the UI according to the company’s style guide.