Consistency and standards constitute the fourth of Jakob Nielsen's ten heuristics.^[1] A good system should use the same patterns everywhere and follow platform- and domain-specific conventions.

Consistency is not about limiting designers' creativity and making all products look alike. Instead, applications that follow standards are more predictable to users, are easier to learn, and cause less cognitive load.

Placing a logo in the same top-left corner on each page, using a house icon for a home page, locating secondary destinations like Settings inside a sidebar menu, and using the same color for active elements (buttons or links) — these familiar patterns help users navigate, feel more comfortable, get used to a new app faster, and reduce confusion.