new Vue({
el: '#root',
data: {
message: 'Hello world'
}
})
<html>
<body>
<div id="root">
<input type="text" id="input" v-model="message">
<p>
Message: {{ message }}
</p>
</div>
</body>
<script src="https://cdn.jsdelivr.net/npm/vue"></script>
</html>