Vue.js: What is the difference between isRef and isReactive in Vue 3?

1import { ref, reactive, isRef, isReactive, computed } from "vue"
2
3const count = ref(0)
4const state = reactive({ count: 0 })
5const doubled = computed(() => count.value * 2)
6
7console.log(isRef(count))  // true
8console.log(isRef(doubled))  // true (computed is ref)
9console.log(isRef(42))  // false
10
11console.log(isReactive(state))  // true
12console.log(isReactive(count))  // false