A

Algorithm

A set of systems and processes used by a search engine to discover,
evaluate, organize, and rank information.

Alt Text

Alternative text added to an image to describe its content.
Alt text helps with accessibility and can also help search systems
understand what an image represents.

Anchor Text

The visible, clickable text of a hyperlink. Anchor text can provide
context about the page being linked to.

Authority

A general SEO concept describing how trustworthy, established, or
influential a website or page may appear based on factors such as links,
reputation, content, and relevance.

B

Backlink

A link from one website to another. Backlinks can help search engines
discover pages and may contribute to how a site’s relevance or
prominence is evaluated.

Black Hat SEO

A broad term for aggressive or manipulative SEO tactics intended to
influence search rankings in ways that may violate search engine
guidelines.

Bot

An automated program that performs tasks across the web. Search engines
use bots, often called crawlers or spiders, to discover and process
webpages.

C

Canonical URL

The preferred version of a page when multiple URLs contain identical
or very similar content. A canonical tag can help indicate which URL
should be treated as the primary version.

Click-Through Rate (CTR)

The percentage of impressions that result in clicks.

A simple formula is:
Clicks ÷ Impressions × 100

Content Cluster

A group of related pages organized around a broader topic, often
connected through internal links.

Core Web Vitals

A group of user experience metrics focused on aspects such as loading,
responsiveness, and visual stability.

Crawl

The process of discovering and accessing webpages through automated
search engine crawlers.

Crawl Budget

A general term describing how much crawling activity a search engine may
devote to a website during a given period.

D

Domain Authority

A third-party SEO metric intended to estimate the relative ranking
strength of a domain. Different SEO tools may calculate authority
metrics using different methods.

Duplicate Content

Content that appears identically or very similarly across multiple URLs.

Duplicate content does not automatically mean a penalty, but it can make
it harder for search engines to determine which version should be shown
or prioritized.

E

External Link

A link from one website to another domain.

Evergreen Content

Content designed to remain useful and relevant for a long period rather
than depending primarily on short-lived news or trends.

G

Google Search Console

A website management and search performance platform provided by Google.
It can show information about search queries, clicks, impressions,
indexing, crawling, and other website issues.

Googlebot

The name commonly used for Google’s web crawler.

H

Heading Tags

HTML elements such as H1, H2, H3, and H4 used to structure page
headings and subheadings.

A logical heading structure can make content easier for both readers and
machines to understand.

HTTPS

The secure version of HTTP. HTTPS encrypts data transferred between a
visitor’s browser and a website.

I

Impression

A measurement indicating that a search result, advertisement, or other
item was displayed to a user.

Index

A search engine’s collection of processed webpages and information that
may be considered for search results.

Indexing

The process through which a search engine processes information from a
page and may add it to its searchable index.

Internal Link

A hyperlink connecting one page of a website to another page on the same
website.

Internal Linking

The practice of creating links between related pages within the same
website to improve navigation, contextual relationships, and site
structure.

K

Keyword

A word or phrase associated with what people search for and the topics
covered by a webpage.

Keyword Difficulty

A third-party SEO metric estimating how competitive it may be to rank
for a particular search query.

Keyword difficulty is not a universal search engine metric and can vary
significantly between SEO tools.

Keyword Research

The process of identifying and analyzing search queries, topics,
audience needs, competition, and search intent.

Keyword Stuffing

Excessive or unnatural repetition of keywords in an attempt to influence
search rankings.

L

Landing Page

A page designed around a particular user intent, campaign, product,
service, topic, or conversion goal.

Link Building

The process of earning, creating, or acquiring links from other websites.

Link Equity

An informal SEO term describing the value or influence that may pass
through a link from one page to another.

Long-Tail Keyword

A more specific search query that often has narrower intent than a broad
head term.

Long-tail queries may individually receive less search volume but can
collectively represent significant search demand.

M

Meta Description

An HTML element that provides a short description of a webpage.
Search engines may use it when generating a search result snippet,
although they may also generate their own description.

Meta Robots

Instructions placed in page metadata that can communicate preferences
related to indexing and search engine behavior.

N

Nofollow

A link attribute used to indicate a particular relationship between the
linking page and destination.

Noindex

A directive that requests that a page not be included in a search
engine’s index.

O

Off-Page SEO

SEO activities and signals that exist outside the website itself,
commonly including backlinks, mentions, reputation, and broader
web presence.

On-Page SEO

The optimization of elements on a webpage, including content, headings,
titles, internal links, images, and other page-level elements.

Organic Search

Unpaid search engine results and the traffic generated through those
results.

P

Page Speed

A general term describing how quickly a webpage loads and becomes usable
for visitors.

Page Title

The title element of a webpage. It can appear in browser tabs and may
also be used by search engines when generating search result titles.

Pillar Page

A broad, comprehensive page covering a central topic and often linking
to more specific supporting articles.

R

Redirect

A method of sending visitors and search engines from one URL to another.

301 Redirect

A redirect commonly used when a page or URL has moved permanently.

302 Redirect

A redirect commonly associated with temporary URL changes.

Robots.txt

A file located at the root of a website that provides crawling
instructions for compatible web crawlers.

Robots.txt primarily affects crawling and should not automatically be
treated as an indexing control.

S

Schema Markup

Structured data added to webpages to help machines better understand
entities, content types, and relationships.

Search Engine Results Page (SERP)

The page displayed by a search engine after a user performs a search.

Search Intent

The underlying goal or need behind a search query.

Search intent is often discussed using categories such as informational,
navigational, commercial, and transactional intent.

Search Volume

An estimate of how frequently a keyword or search query is searched
during a specific period.

Search volume figures are usually estimates and can differ between
keyword research tools.

Sitemap

A file or page that helps organize and communicate website URLs.

XML Sitemap

A machine-readable sitemap that can help search engines discover
important URLs on a website.

Structured Data

Standardized markup that provides machines with additional information
about the meaning and structure of webpage content.

T

Technical SEO

The part of SEO focused on technical systems that influence how search
engines access, crawl, render, understand, and index a website.

Title Tag

Another commonly used term for the HTML title element of a webpage.

Topic Cluster

A content structure where multiple related pages support a broader
central topic and are connected through internal links.

U

URL

The web address used to identify a resource on the internet.

URL Slug

The portion of a URL that commonly identifies a specific page.

For example, in:
example.com/technical-seo-guide/
the slug is technical-seo-guide.

SEO Metrics Are Not All the Same

One important distinction when reading SEO material is the difference
between search engine data and third-party SEO metrics.

Third-party metrics can be useful for comparison and research, but they
should not automatically be treated as direct search engine ranking
factors.

Glossary Updates

Search terminology changes as search engines, websites, AI systems,
analytics platforms, and SEO practices evolve.

AF Search may expand or update this glossary as new concepts become
relevant.

Looking for a term that is not listed here?
Visit our Contact page and suggest an addition.