Difference between Vue 2 and Vue 3

[xfq]

https://vuejs.org/about/faq.html#what-s-the-difference-between-vue-2-and-vue-3

Vue 3 is the current, latest major version of Vue. It contains new features that are not present in Vue 2 (most notably Composition API), and also contains breaking changes that makes it incompatible with Vue 2. Despite the differences, the majority of Vue APIs are shared between the two major versions, so most of your Vue 2 knowledge will continue to work in Vue 3.

Vue 2.7 has Composition API now.