Vue.js: What is the difference between defineExpose and public API?

defineExpose — expose methods. script setup — private by default.

defineExpose:

• Expose to parent.
• Explicit API.
• Script setup default: private.

Without defineExpose:

• Nothing exposed.
• Parent cannot access.
• Encapsulated.

1<!-- Child -->
2<script setup>
3const reset = () => { /* ... */ }
4defineExpose({ reset })
5</script>
6
7<!-- Parent -->
8<script setup>
9import { ref } from "vue"
10const child = ref(null)
11child.value.reset()  // OK
12</script>

Key: defineExpose for parent access.