Directives are used with a markup language to perform some functions on the DOM elements. For example, in HTML markup language, when we write:
<div class='app'></div>
The class used here is a directive for HTML language. Similarly, Vue.js also provides a lot of such directives to make application development easier, such as:
- v-text
 - v-on
 - v-ref
 - v-show
 - v-pre
 - v-transition
 - v-for