Vue.js: What is the difference between shallowRef and ref?

1<script setup>
2import { ref, shallowRef } from "vue"
3
4const deep = ref({ nested: { value: 0 } })
5deep.value.nested.value++  // Triggers
6
7const shallow = shallowRef({ nested: { value: 0 } })
8shallow.value.nested.value++  // Does NOT trigger
9shallow.value = { nested: { value: 1 } }  // Triggers
10</script>