seo-fundamentals

这段内容是审核时保存的快照。外部来源才是完整且最新的版本。

---
name: seo-fundamentals
description: Core principles of SEO including E-E-A-T, Core Web Vitals, technical foundations, content quality, and how modern search engines evaluate pages.
risk: safe
source: community
date_added: '2026-02-27'
---

# SEO Fundamentals

> **Foundational principles for sustainable search visibility.**
> This skill explains _how search engines evaluate quality_, not tactical shortcuts.

---

## 1. E-E-A-T (Quality Evaluation Framework)

E-E-A-T is **not a direct ranking factor**.
It is a framework used by search engines to **evaluate content quality**, especially for sensitive or high-impact topics.

| Dimension             | What It Represents                 | Common Signals                                      |
| --------------------- | ---------------------------------- | --------------------------------------------------- |
| **Experience**        | First-hand, real-world involvement | Original examples, lived experience, demonstrations |
| **Expertise**         | Subject-matter competence          | Credentials, depth, accuracy                        |
| **Authoritativeness** | Recognition by others              | Mentions, citations, links                          |
| **Trustworthiness**   | Reliability and safety             | HTTPS, transparency, accuracy                       |

> Pages competing in the same space are often differentiated by **trust and experience**, not keywords.

---

## 2. Core Web Vitals (Page Experience Signals)

Core Web Vitals measure **how users experience a page**, not whether it deserves to rank.

| Metric  | Target  | What It Reflects    |
| ------- | ------- | ------------------- |
| **LCP** | < 2.5s  | Loading performance |
| **INP** | < 200ms | Interactivity       |
| **CLS** | < 0.1   | Visual stability    |

**Important context:**

- CWV rarely override poor content
- They matter most when content quality is comparable
- Failing CWV can _hold back_ otherwise good pages

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## 3. Technical SEO Principles

Technical SEO ensures pages are **accessible, understandable, and stable**.

### Crawl & Index Control

| Element           | Purpose                |
| ----------------- | ---------------------- |
| XML sitemaps      | Help discovery         |
| robots.txt        | Control crawl access   |
| Canonical tags    | Consolidate duplicates |
| HTTP status codes | Communicate page state |
| HTTPS             | Security and trust     |

### Performance & Accessibility

| Factor                 | Why It Matters                |
| ---------------------- | ----------------------------- |
| Page speed             | User satisfaction             |
| Mobile-friendly design | Mobile-first indexing         |
| Clean URLs             | Crawl clarity                 |
| Semantic HTML          | Accessibility & understanding |

---

## 4. Content SEO Principles

### Page-Level Elements

| Element          | Principle                    |
| ---------------- | ---------------------------- |
| Title tag        | Clear topic + intent         |
| Meta description | Click relevance, not ranking |
| H1               | Page’s primary subject       |
| Headings         | Logical structure            |
| Alt text         | Accessibility and context    |

### Content Quality Signals

| Dimension   | What Search Engines Look For |
| ----------- | ---------------------------- |
| Depth       | Fully answers the query      |
| Originality | Adds unique value            |
| Accuracy    | Factually correct            |
| Clarity     | Easy to understand           |
| Usefulness  | Satisfies intent             |

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## 5. Structured Data (Schema)

Structured data helps search engines **understand meaning**, not boost rankings directly.

| Type           | Purpose                |
| -------------- | ---------------------- |
| Article        | Content classification |
| Organization   | Entity identity        |
| Person         | Author information     |
| FAQPage        | Q&A clarity