design system
A shared rulebook and parts kit for building interfaces
A design system is a company's agreed set of ready-made interface parts, such as buttons and cards. It also fixes the colors, spacing and type styles those parts may use. Teams build from it so products look and behave consistently. Without it, every screen drifts toward its own style.
Think of it as
Like a franchise brand manual: every branch uses the same signage, colors and layout, so customers recognise it anywhere.