What is the difference between the parent and child components of vue and the local global components?

I only know global components and local components. I don"t know what parent-child components are, nor do I introduce the tutorials on the Internet. I just talked about parent-child communication and passing values. Which god can explain the parent-child component?

Apr.05,2021

is to use another component in a component to form a parent-child relationship

for example, using component2
component1 in component1 is the parent component of component2
component2 is a child component of component1

//component1.vue
<template>
   <div>
        <component2></component2>
   </div>
<template>
...
import component2 from 'component2.vue'

@ Zany
I am a novice. Thank you for replying to me. Maybe I didn't read the official tutorial carefully enough or didn't quite understand your answer. Please see the example below.

<div id="app-4">
     <div id="app-5" :style="{ fontSize: postFontSize + 'em' }" >
        <blog-post3 v-for="post in posts" v-bind:post="post" v-bind:key="post.id" v-on:enlarge-text="postFontSize += 0.1 "> </blog-post3>
    </div>
</div>

<script>
    Vue.component('blog-post3', {
       props: ['post'],
       template: `
        <div>
            <h3> {{ post.title }}</h3>
            <button v-on:click="$emit('enlarge-text')">enlarge text</button>
            <div v-html="post.content"></div>
        </div>`
    });
    var app4 = new Vue({
      el: '-sharpapp-4',
      data: {
        posts: [
          { id: 1, title: 'My journey with Vue', content: '...content...' },
          { id: 2, title: 'Blogging with Vue', content: '...content...' },
          { id: 3, title: 'Why Vue is so fun', content: '...content...' }
        ],
        postFontSize: 1
      }
    });
</script>

in this example, can it be understood that < div id= "app-4" > is the parent component and < blog-post3 > is its child component after app-4 instantiation.
if not, what is the component of the div you are talking about?


< hr >


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