Vue.js is a popular JavaScript front-end framework that provides a concise and flexible way to build interactive user interfaces. In Vue.js, we usually create a root instance and then build the entire application through components.
In Vue.js, you really only need one root instance. This root instance is the entry point of the Vue.js application, and all components are created and managed under the control of the root instance. The root instance is responsible for initializing the Vue.js application and mounting it on a DOM element on the HTML page.
Here is a simple example showing how to create a root instance of Vue.js:
// 创建一个 Vue 根实例
new Vue({
el: '#app', // 指定根实例要挂载到的 DOM 元素
data: {