Alias tokens, also known as reference tokens, are a powerful feature in design token systems. They allow tokens to reference the value of another token, creating a dynamic relationship between tokens. Instead of duplicating values across multiple tokens, alias tokens can be used to reference a single source of truth, reducing redundancy and making updates more efficient.

Alias tokens also provide flexibility in managing token values. If the value of the referenced token changes, all the alias tokens that reference it will automatically update as well, ensuring consistency throughout the design system. This makes it easy to make updates to a token's value in one place, and have it reflected across all the tokens that reference it.