Without a design system, every designer and developer makes small decisions on their own: a slightly different blue, a new button style, another spacing value. After a year the product has dozens of near-duplicates. A design system replaces those repeated decisions with shared ones.
Most design systems have three layers. Design tokens are named values, such as color.primary, space.4 or motion.duration.short, that store the raw decisions. Components, such as buttons, inputs, cards and dialogs, are built from those tokens and include every state. Guidelines document how to use each component, how to write labels and messages, and what accessibility rules apply.
A design system lives in two places: in the design tool, as a component library, and in code, as a package developers install. Keeping those two in sync is the hardest part. When the coded button no longer matches the designed one, people stop trusting the system.
Motion belongs in the system too. Durations, easing curves and spring settings can be tokens, and interactive components need defined behaviour for hover, press, loading and transitions. ExodeUI, which we make, stores that behaviour in one open file with states and spring physics, so the same component plays in React, Vue, SwiftUI, Flutter and other frameworks.
Well-known public examples include Google's Material Design, Apple's Human Interface Guidelines, IBM's Carbon and Shopify's Polaris. Reading them is a good way to see how a mature system is organised.