Voice and Tone in a Design System refer to the consistent and intentional use of language across the user interface components in a Design System or component library. It defines the personality, style, and attitude of the interface, creating a cohesive and harmonious user experience.

By defining a clear Voice and Tone, teams ensure a consistent and coherent user experience, regardless of the number of contributors or the complexity of the UI library. To use voice and tone effectively, guidelines are documented that outline the preferred language style, vocabulary, and communication approach for different components. These guidelines help maintain a unified and recognizable interface, ensuring that all interactions align with the overall design vision and meet user expectations.