1npm install -g @vue/cli
2# OR
3yarn global add @vue/cli

1npm install vue

1/*for development ===>*/ <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
2/*for production ===>*/ <script src="https://cdn.jsdelivr.net/npm/vue@2.6.11"></script>
3

1npm install -g vue-cli    //make sure you have node and npm installed 
2vue init webpack <appname>  //  eg:  vue init webpack myapp
3cd <appname>               // cd myapp
4npm install
5npm run dev  //server will start in port 8080

1npm install -g @vue/cli   
2yarn global add @vue/cli

1<!-- development version, includes helpful console warnings -->
2<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>