2nd/10_Wiki/Topics/AI_and_ML/DOM vs Virtual DOM.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-dom-vs-virtual-dom	DOM vs Virtual DOM	10_Wiki/Topics	verified	self	DOM Virtual DOM vDOM reconciliation diffing React fiber Solid signals Svelte compile	none	A	0.93	applied	frontend dom virtual-dom react fiber solid svelte signals fine-grained-reactivity		2026-05-10	pending	language framework JavaScript / React / Solid / Svelte React / Solid / Svelte / Vue

DOM vs Virtual DOM

매 한 줄

"매 DOM mutation 의 expensive — 매 abstraction 의 batch". React 의 Virtual DOM (2013). 매 modern: 매 fine-grained reactivity (Solid, Svelte, Vue 3) 의 vDOM 의 supersede 의 trend. 매 pure DOM (vanilla, htmx) 의 revival.

매 핵심

Real DOM

• 매 browser 의 tree.
• 매 mutation 의 reflow / repaint 의 trigger.
• 매 manual update 의 error-prone.

Virtual DOM (React)

• 매 lightweight JS object 의 in-memory.
• 매 declarative state.
• 매 diff + 매 reconciliation 의 minimal real DOM update.

매 React 의 algorithm

1. 매 새 Virtual DOM tree.
2. 매 diff vs 매 previous (heuristic O(n)).
3. 매 minimal real DOM mutation.

매 React 의 heuristic

• Different type → 매 entirely new tree.
• key attribute → 매 stable child identity.
• Component type same + props different → 매 update only changed.

매 modern alternative

Fine-grained reactivity (Solid, Svelte 5, Vue 3)

• 매 vDOM 의 X.
• 매 signal / effect 의 specific DOM 의 update.
• 매 faster + smaller bundle.

Compile-time (Svelte)

• 매 framework 의 compile away.
• 매 매 component 의 specific imperative code.

htmx / Pure HTML

• 매 server-side render + 매 partial swap.
• 매 매 minimum JS.

매 trade-off

측면	Real DOM	Virtual DOM	Fine-grained
Direct manipulation	Manual	Abstracted	Abstracted
Update granularity	Per-mutation	Per-component	Per-signal
Memory	Low	Medium	Low
Bundle size	Tiny	50KB+ (React)	<10KB (Solid)
Rendering speed	Variable	Good	Best
Mental model	Imperative	Declarative + render fn	Declarative + signals

매 React Fiber (2017)

• 매 reconciliation 의 interruptible.
• 매 priority-based.
• 매 concurrent rendering.
• 매 React 18+ default.

매 modern React 18+ optimization

• Concurrent rendering: 매 interrupt.
• Automatic batching.
• Suspense + streaming.
• useTransition / useDeferredValue.
• RSC (Server Components).

매 응용

1. Large dynamic UI: React / Solid.
2. Static + light interactivity: htmx / Astro islands.
3. Form-heavy: Solid (fast).
4. SEO-critical: Next.js (SSR).
5. Data viz: D3 + minimal framework.

💻 패턴

React (declarative)

function Counter() {
  const [count, setCount] = useState(0);
  return (
    <button onClick={() => setCount(count + 1)}>
      Count: {count}
    </button>
  );
}
// React 가 매 setCount 시 의 새 vDOM → diff → 매 button text 만 update.

key for stable identity

function List({ items }) {
  return (
    <ul>
      {items.map(item => (
        <li key={item.id}>{item.name}</li>  // 매 key 의 stable identity
      ))}
    </ul>
  );
}

useMemo / React.memo

const ExpensiveItem = React.memo(({ item, onClick }) => (
  <div onClick={onClick}>{item.name}</div>
));

function List({ items, onSelect }) {
  // 매 stable callback for memoization
  const handleSelect = useCallback((id) => onSelect(id), [onSelect]);
  
  const sorted = useMemo(() => 
    items.sort((a, b) => a.priority - b.priority), [items]);
  
  return sorted.map(item => 
    <ExpensiveItem key={item.id} item={item} onClick={handleSelect} />
  );
}

Solid (signals, no vDOM)

import { createSignal } from 'solid-js';

function Counter() {
  const [count, setCount] = createSignal(0);
  return (
    <button onClick={() => setCount(count() + 1)}>
      Count: {count()}
    </button>
  );
}
// 매 specific text node 의 update — 매 component re-render X.

Svelte (compile-time)

<script>
  let count = 0;
</script>

<button on:click={() => count++}>
  Count: {count}
</button>

<!-- 매 compile 의 imperative code 의 generate -->

Vue 3 (Proxy-based reactivity + vDOM)

<script setup>
import { ref } from 'vue';
const count = ref(0);
</script>

<template>
  <button @click="count++">Count: {{ count }}</button>
</template>

htmx (no JS framework)

<button hx-post="/click" hx-target="#count" hx-swap="innerHTML">
  Click me
</button>
<span id="count">0</span>

<!-- 매 server 가 매 HTML 의 return → 매 swap -->

Direct DOM (vanilla)

const button = document.querySelector('button');
let count = 0;
button.addEventListener('click', () => {
  count++;
  button.textContent = `Count: ${count}`;  // 매 direct mutation
});

Concurrent rendering (React 18+)

import { useTransition, useDeferredValue } from 'react';

function SearchableList({ items }) {
  const [filter, setFilter] = useState('');
  const deferred = useDeferredValue(filter);
  
  const filtered = items.filter(i => i.name.includes(deferred));
  
  return (
    <>
      <input value={filter} onChange={e => setFilter(e.target.value)} />
      <List items={filtered} />
    </>
  );
}

Performance comparison (React vs Solid)

// 매 typical bench:
// React useState + setCount: 매 10K updates → 매 500ms
// Solid signal + setCount: 매 10K updates → 매 50ms (10×)

<picture> and DOM (no framework)

<picture>
  <source srcset="/img.avif" type="image/avif">
  <img src="/img.jpg" alt="..." width="800" height="600">
</picture>
<!-- 매 HTML primitive 의 사용 -->

매 결정 기준

상황	Approach
Large dynamic SPA	React + Concurrent
Performance-critical	Solid / Svelte
SEO + static + light JS	Astro + Islands
Form-heavy	Solid
Server-driven	htmx + HTML
Data viz	D3 + minimal
Vanilla / lib-free	Direct DOM

기본값: React for ecosystem. Solid / Svelte for performance.

🔗 Graph

• 부모: Frontend · Web-Performance · React
• 변형: Virtual DOM · Fine-Grained-Reactivity
• 응용: React · Solid · Vue-3 · htmx · Astro
• Adjacent: Critical_Rendering_Path · CSS Animations · Core Web Vitals Optimization (INP, LCP 개선) · Container_Queries

🤖 LLM 활용

언제: 매 framework selection. 매 perf optimization. 매 bundle size 의 reduce. 언제 X: 매 backend (다른 paradigm).

❌ 안티패턴

• Direct DOM mutation in React: 매 desync.
• key={index} for dynamic list: 매 wrong reconciliation.
• No memoization (heavy re-render): 매 perf.
• Premature memoization: 매 over-engineering.
• vDOM 의 large overhead (small list): 매 vanilla 의 더 빠름.

🧪 검증 / 중복

• Verified (React docs, Solid docs, Svelte performance benchmark).
• 신뢰도 A.
• Related: Critical_Rendering_Path · CSS Animations · Core Web Vitals Optimization (INP, LCP 개선) · Container_Queries · Case-Study-Allbirds-PWA-Redesign.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — DOM vs vDOM vs fine-grained + 매 React / Solid / Svelte / htmx code