What is the difference between annotations and decorators in Angular?

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Two ways to add metadata in JavaScript/TypeScript ecosystems. Angular uses decorators exclusively in modern code. Decorators — TypeScript syntax ( @Decorator ); functions executed at runtime that modify or annotate the target. Standard in modern Angular. Annotations — older AngularJS-era pattern; metadata stored as a static property on the class. Survived briefly during Angular 2 alpha; gone now. Both attach metadata — the framework reads it to know how to use the class. Decorators are language-level — part of TypeScript / Stage 3 ECMAScript; tooling supports them widely. In practice — you only ever write decorators in Angular today; the term &ldquo;annotation&rdquo; appears in older Angular 2 docs. Annotations were AtScript's passive metadata array; decorators are TS functions that actively receive and modify the target. Modern Angular uses **decorators only** — annotations are dead history.