Design tokens are a limited set of discrete options, just like a scale of musical notes is drawn from the spectrum of all possible frequencies. Or like the presets on a car radio — not every option, just a specific selection.— US Web Design System
Design tokens are organized under token tiers, which are high-level containers that allow you to manage and organize your design tokens in a structured manner.
Token tiers are used to group related design tokens with a specific use case together. For example, you could have token tiers like 'Global' or 'Base tokens', 'Semantic Tokens', and 'Component Tokens'.
Under each token tier, you can define tokens of any category, such as 'Colors', 'Typography', 'Spacing', etc., depending on your specific design system requirements.
You can enable contextual token overrides for each token tier. See the next section Brands & Contexts for defining contexts.