What is the difference between ref and reactive in Vue.js?

In Vue.js, ref and reactive are two ways to create reactive data, but they have different purposes and features.

• ref creates a reactive object with a single property .value. It is used for primitive values (numbers, strings, booleans) or when you need to wrap a single value in reactivity.

  import { ref } from 'vue';
  const count = ref(0);
  count.value++;
  

• reactive creates a reactive object from an object or array. It returns a proxy object that tracks changes to all nested properties.

  import { reactive } from 'vue';
  const state = reactive({ count: 0 });
  state.count++;
  

Main differences:

• ref is used for primitives or when you need to reactively track a single value.
• reactive is used for reactivity of complex objects and data structures.
• When using ref for objects, access to the value is through .value, while with reactive — directly.

In Vue 3, both approaches are often combined depending on the situation to manage reactivity effectively.