SEO & Link Building Glossary
Clear definitions for the terms you encounter when managing website links and technical SEO.
404 Error
What happens when a page can't be found — and how it affects SEO.
301 Redirect
The permanent redirect that preserves link equity and guides users.
Crawl Budget
How search engines allocate resources to crawl your site — and why broken links waste it.
Broken Link
A hyperlink that no longer leads to its intended destination.
Redirect Chain
Multiple redirects in sequence that slow down pages and dilute SEO value.
Link Rot
The gradual decay of links over time as pages move or disappear.
Dead Link
A hyperlink that points to a page or resource that no longer exists.
Soft 404
A page that returns HTTP 200 but displays error content instead of useful information.
HTTP Status Codes
Three-digit server response codes that indicate the result of an HTTP request.
Anchor Text
The visible, clickable text of a hyperlink that describes where the link leads.
302 Redirect
The temporary redirect — when to use it and how it differs from a 301.
Canonical URL
The preferred version of a page — preventing duplicate content issues.
robots.txt
The file that tells crawlers which parts of your site they can access.
XML Sitemap
The map you give search engines to discover and prioritize your pages.
hreflang
The HTML attribute that tells search engines which language version to serve.
Meta Description
The snippet under your title in search results — what users actually read.
noindex
The directive that keeps a page out of search engine indexes.
nofollow
The link attribute that tells search engines not to pass ranking signals.
Internal Link
Links between pages on the same domain — the backbone of site structure.
External Link
Links pointing to another domain — outbound trust signals.
Backlink
An inbound link from another site — the original ranking signal.
Link Equity
The ranking value passed through links — also known as "link juice".
500 Internal Server Error
The catch-all error returned when a server-side problem prevents page rendering.
503 Service Unavailable
The status code that signals temporary downtime — often used during maintenance.
DNS Error
A failure to resolve a domain name to its server — the request never even starts.
SSL Certificate
The cryptographic credential that enables HTTPS — and that search engines expect.
www vs non-www
Choosing the canonical hostname — and why consistency matters more than the choice itself.
Mixed Content
When an HTTPS page loads HTTP resources — a security and SEO problem.
Redirect Loop
When redirects circle back on themselves and the page never loads.
User-Agent
The HTTP header identifying the client — and what servers use to decide what to serve.
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