App.vue
AnimalCollection.vue
FoodItems.vue
main.js
 
<template>
  <p>Choose what part of this page you want to see:</p>
  <button @click="activeComp = 'animal-collection'">Animals</button>
  <button @click="activeComp = 'food-items'">Food</button><br>
  <div>
    <component :is="activeComp"></component>
  </div>
</template>

<script>
export default {
  data() {
      return {
        activeComp: ''
      }
    }
}
</script>

<style scoped>
  button {
    padding: 5px;
    margin: 10px;
  }
  div {
    border: dashed black 1px;
    padding: 20px;
    margin: 10px;
    display: inline-block;
  }
</style>                  
<template>
    <h1>Animals!</h1>
    <p>I want to learn about at least one new animal every year.</p>
</template>                  
<template>
    <h1>Food!</h1>
    <p>I like most types of food.</p>
</template>                  
import { createApp } from 'vue'

import App from './App.vue'
import FoodItems from './components/FoodItems.vue'
import AnimalCollection from './components/AnimalCollection.vue'

const app = createApp(App)
app.component('food-items', FoodItems);
app.component('animal-collection', AnimalCollection);

app.mount('#app')
                  
http://localhost:5173/