SEO & Link Building Glossary: Every Term You Need to Know

New to SEO? Or just want to clarify some technical terms?

This glossary covers the essential definitions of search engine optimization and link building. From basics to advanced concepts, it's all here.

Use the table of contents to quickly navigate to the term you're looking for.

A

Algorithm (Google)

A set of rules and calculations used by Google to rank web pages in its search results. Major algorithms include Panda (content quality), Penguin (link quality), and Core Updates (broad changes).

Anchor Text

The clickable text of a hyperlink. Anchor text gives Google signals about the content of the destination page. An optimized anchor contains relevant keywords, but over-optimization can trigger penalties.

Example: In <a href="...">SEO tools</a>, the anchor text is "SEO tools".

Authority (Domain Authority)

A score developed by Moz (from 0 to 100) that predicts how well a site will rank in search results. The higher the score, the more "powerful" the site is considered. Not an official Google metric.

B

Backlink

An incoming link from an external site to your website. Backlinks are one of the most important ranking factors for Google. A quality backlink comes from a relevant, trustworthy site with authority in its field.

Synonyms: inbound link, incoming link, external link

Black Hat SEO

SEO techniques that violate Google's guidelines to achieve quick results. Examples: massive link buying, cloaking, automated duplicate content. These practices risk manual or algorithmic penalties.

Broken Link

A link pointing to a non-existent page (404 error). Broken links hurt user experience and can negatively affect your SEO. A monitoring tool can detect them automatically.

C

Canonical Tag

An HTML tag (rel="canonical") that tells Google which is the main version of a page when multiple URLs display similar content. Helps avoid duplicate content issues.

Citation Flow (CF)

A metric developed by Majestic that measures the quantity of links pointing to a URL or domain. Should be used alongside Trust Flow to evaluate link profile quality.

Cloaking

A Black Hat technique that displays different content to search engines and users. Strictly prohibited by Google and subject to penalties.

Crawl / Crawler

The action of search engine robots (Googlebot, Bingbot...) exploring the web. The crawler visits pages by following links to index content.

D

Disavow

A procedure to ask Google to ignore certain toxic backlinks pointing to your site. Done via Google Search Console with a .txt file listing the links to disavow.

Dofollow

The default attribute of a hyperlink. A dofollow link passes "link juice" to the destination page and can positively influence its ranking.

Domain Rating (DR)

A score developed by Ahrefs (from 0 to 100) that evaluates the strength of a domain's backlink profile. The higher the DR, the more authoritative the site is considered.

E

E-E-A-T

Acronym for Experience, Expertise, Authoritativeness, Trustworthiness. Criteria used by Google to evaluate content quality, particularly important for YMYL topics.

Editorial Link

A link naturally placed within content by an editor or author because they find the linked resource valuable. The most valuable type of backlink.

F

Footer Link

A link placed in a website's footer. Site-wide footer links (present on all pages) are generally less valued by Google as they're considered less natural.

G

Google Penguin

A Google algorithm update (2012) targeting sites with artificial or low-quality link profiles. Since 2016, Penguin is part of the core algorithm and works in real-time.

Google Search Console

A free Google tool for monitoring your site's presence in search results. Provides data on backlinks, crawl errors, search performance, and more.

Guest Posting

A link building technique involving writing an article for another site in exchange for one or more backlinks. A legitimate method if the content provides real value to readers.

H

HTTP Status Code

A response code returned by a web server. Key codes to know:

• 200: OK (page accessible)
• 301: Permanent redirect
• 302: Temporary redirect
• 404: Page not found
• 500: Server error

I

Indexing

The process by which Google adds a web page to its index (database). A non-indexed page won't appear in search results.

Internal Link

A link pointing to another page on the same website. Internal linking helps search engines understand your site structure and distributes link juice between your pages.

K

Keyword

A term or phrase users type into search engines. Keyword optimization is at the heart of on-page SEO.

L

Link Building

All actions aimed at acquiring backlinks to your site. Common strategies: guest posting, creating linkable content, press relations, broken link building...

Link Farm

A group of websites created solely to link to each other or to a target site. A Black Hat technique that's easily detected and penalized by Google.

Link Juice

A colloquial term for the SEO value passed by a backlink. A dofollow link from an authoritative site passes more "juice" than a nofollow link from a small site.

Link Profile

The collection of all backlinks pointing to a site. A healthy link profile is diverse (varied sources, natural anchors) and comes from relevant sites.

Link Velocity

The speed at which a site acquires new backlinks. A sudden, unnatural increase can be a manipulation signal for Google.

Linkbait

Content created specifically to attract natural backlinks. Examples: original studies, infographics, free tools, controversial or emotional content.

M

Manual Action

A penalty manually applied by a Google employee following a guideline violation. Visible in Google Search Console, it requires a reconsideration request after correction.

Mention (Brand Mention)

A citation of your brand or site without a hyperlink. Some SEOs believe Google may use unlinked mentions as a notoriety signal.

N

Natural Link

A backlink obtained without direct solicitation, simply because a site found your content useful and decided to reference it. The type of link most valued by Google.

Nofollow

A link attribute (rel="nofollow") that tells search engines not to follow the link or pass link juice. Originally created to combat comment spam.

Noindex

A directive telling search engines not to index a page. A noindexed page generally doesn't pass (or passes little) SEO value through its outbound links.

O

Outbound Link

A link from your site to an external website. Outbound links to reliable sources can improve your content's credibility in Google's eyes.

Over-optimization

Excessive optimization of a site or its link profile. Example: too many exact-match anchors on your backlinks. Can trigger algorithmic penalties.

P

PageRank

A historical Google algorithm (created by Larry Page) that evaluates a page's importance based on the quantity and quality of links it receives. Public PageRank hasn't been updated since 2016, but the concept remains core to the algorithm.

PBN (Private Blog Network)

A network of sites artificially created to generate backlinks to a main site. A risky Black Hat technique subject to penalties.

Penalty (Google Penalty)

A sanction applied by Google to a site that violates its guidelines. Can be algorithmic (automatic) or manual. Results in ranking drops or deindexing.

R

Reciprocal Link

A mutual link exchange between two sites ("you link to me, I link to you"). Excessive reciprocal linking is considered manipulation and can be penalized.

Redirect 301

A permanent redirect from one URL to another. Transfers most link juice from the old URL to the new one. Essential during site migrations.

Redirect 302

A temporary redirect. Doesn't transfer link juice the same way as a 301. Should only be used for genuinely temporary redirects.

Referring Domain

A unique website containing at least one backlink to your site. 100 links from 10 referring domains generally have more value than 100 links from a single domain.

Rel="sponsored"

A link attribute indicating it's a paid or sponsored link. Recommended by Google for sponsored articles and commercial partnerships.

Rel="ugc"

A link attribute (User Generated Content) for links created by users: comments, forums, etc.

S

SEO (Search Engine Optimization)

The set of techniques aimed at improving a site's position in organic search results. Divided into on-page SEO, technical SEO, and off-page SEO (link building).

SERP (Search Engine Results Page)

A search engine results page. Includes organic results, paid ads, and features (featured snippets, PAA, knowledge panel...).

Sitewide Link

A link present on all pages of a site (header, footer, sidebar). Generally less valued than a unique contextual link as it's less "editorial."

Spam Score

A metric developed by Moz that evaluates the probability that a site is penalized or low-quality. Score from 0% (low risk) to 100% (high risk).

T

Tier 1 / Tier 2 Links

Link building terminology. Tier 1 links point directly to your site. Tier 2 links point to your Tier 1 links to strengthen them. A somewhat outdated strategy.

Toxic Backlink

A backlink from a low-quality, spammy, or penalized site. Can harm your rankings. Solution: request removal or disavow via Google Search Console.

Trust Flow (TF)

A Majestic metric that measures the quality/trustworthiness of links pointing to a site. A site with high TF is considered trustworthy. Should be cross-referenced with Citation Flow.

U

URL Rating (UR)

An Ahrefs score (from 0 to 100) that evaluates the strength of a specific page's backlink profile (unlike Domain Rating which evaluates the entire domain).

W

White Hat SEO

SEO techniques that comply with Google's guidelines. A sustainable and ethical approach to search engine optimization, as opposed to Black Hat SEO.

Conclusion

This glossary covers the essential terms of SEO and link building. You now have the foundation to understand audit reports, communicate with SEO consultants, or deepen your search engine optimization strategy.

Want to go further with managing your backlinks? Learn how to monitor your backlinks automatically with Linkazu.