defineProps is the <script setup> compiler macro for declaring component props in Vue 3, replacing the props option from the Options API with a more concise and TypeScript-friendly syntax. As the creator of CoreUI with Vue development experience since 2014, I use defineProps in every <script setup> component because it gives both runtime validation and full TypeScript type inference without any extra configuration. Choosing between the runtime syntax and the TypeScript generic syntax depends on whether you need complex default values — the TypeScript syntax offers better type safety but requires withDefaults for defaults. Both approaches are idiomatic and supported — choose the one that fits your project’s TypeScript configuration.