This glossary defines the core terms used in directory submission, link building, and technical SEO. Each entry is written to be self-contained — useful whether you are encountering a concept for the first time or need a precise reference.
Directory and listing terms
Directory submission
Directory submission is the process of adding a website's URL, title, and description to a web directory so that the site appears in that directory's listings. It serves three practical purposes: creating a backlink, generating referral traffic from people browsing the directory, and giving search engine crawlers an additional path to discover the page. Whether directory submission still moves the needle for modern SEO is a reasonable question — see does directory submission still work in 2026? for a current assessment.
Web directory
A web directory is a curated catalogue of websites, organised by category and sometimes reviewed by human editors before inclusion. Unlike a search engine, a web directory presents static listings rather than algorithmically ranked results generated from a live crawl. Early examples such as Yahoo! Directory shaped how the web was navigated before search engines became dominant.
Niche directory
A niche directory lists only websites within a specific industry, topic, or geographic area — for example, a directory covering legal firms, software tools, or restaurants in a particular city. Because the linking context is topically relevant, links from niche directories are generally considered more valuable to SEO than links from general-purpose directories.
NAP (Name, Address, Phone number)
NAP stands for Name, Address, Phone number. In local SEO, consistent NAP data across all online directories and mentions signals to search engines that a business is accurately represented, supporting placement in local and map results. Even small inconsistencies — an abbreviated street name on one listing versus a spelled-out version on another — can undermine this consistency signal.
Citation (local SEO)
A citation is any online mention of a business's NAP data, whether or not a hyperlink is included. Citations on directories, review platforms, and data aggregators are a recognised local SEO ranking factor. The total number of citations matters less than their accuracy and the authority of the sites they appear on.
Backlink and authority terms
Backlink
A backlink is any hyperlink on an external website that points to your site. Search engines treat backlinks as a form of endorsement: a page that many authoritative, relevant sites link to is generally considered more trustworthy than one with few or no inbound links. Not all backlinks carry equal weight — the authority of the linking page, its relevance to your content, and the link's attributes all affect the value it passes.
Do-follow link
A do-follow link is a hyperlink that carries no attribute telling search engine crawlers to ignore it, so link equity flows from the linking page to the destination. It is the default link type and what most link-building efforts aim to acquire. The label "do-follow" is informal; the technical reality is simply the absence of a disqualifying attribute.
No-follow link, rel="sponsored", and rel="ugc"
A no-follow link uses the rel="nofollow" attribute to signal that the linking site does not wish to endorse the destination. Google introduced this attribute in 2005 primarily to combat comment spam. In 2019, two more granular values were added: rel="sponsored" for paid placements and advertorials, and rel="ugc" for links inside user-generated content such as forum posts or comments. Google treats all three as hints rather than hard directives. No-follow and its variants still drive referral traffic and can assist crawl discovery, even when they pass little or no link equity.
Anchor text
Anchor text is the visible, clickable text of a hyperlink. Search engines use it as a relevance signal, inferring what the destination page covers from the words chosen. A natural backlink profile mixes branded anchors (your company name), exact-match anchors (a target keyword), partial-match anchors, and generic phrases such as "click here." A profile dominated by exact-match anchors can look manipulative and may attract algorithmic scrutiny.
Domain Authority (DA)
Domain Authority (DA) is a proprietary 1-100 score developed by Moz to estimate how well a domain is likely to rank in search results. It is calculated from factors including the number and quality of inbound links. DA is a third-party metric; it is not a signal Google uses in its ranking algorithms, but it is widely used in the SEO industry as a benchmarking shorthand.
Domain Rating (DR)
Domain Rating (DR) is Ahrefs' equivalent metric, also on a 0-100 logarithmic scale, reflecting the relative strength of a domain's backlink profile within Ahrefs' index. Like DA, DR is a proprietary score and not a direct Google ranking input. The two scores frequently differ because Moz and Ahrefs index different subsets of the web and use different weighting models.
Link equity (link juice)
Link equity — informally called link juice — is the authority or value that passes from a linking page to a destination page through a hyperlink. It is affected by the authority of the source page, the topical relevance of the linking context, the link's follow status, and how many other outbound links share that same page. Pages with many outbound links distribute less equity per link than pages with few.
Referring domain
A referring domain is a unique external website that contains at least one backlink pointing to your site. SEOs track referring domains alongside raw backlink counts because dozens of links from a single domain typically carry less cumulative value than the same number of links spread across independent sites. Growing a diverse referring-domain base is a core goal of most link-building campaigns.
PBN (private blog network)
A private blog network is a collection of websites built or acquired specifically to manufacture backlinks pointing to a target site. Google's Webmaster Guidelines classify PBN links as a link scheme — a form of manipulation intended to artificially inflate rankings. Sites found to be buying or selling links through a PBN risk a manual action from Google's spam team or an algorithmic ranking demotion. The risk-to-reward profile makes PBNs an approach most SEO practitioners avoid.
Organic traffic
Organic traffic is visitors who arrive at a website by clicking an unpaid search result. It is distinct from paid search traffic, direct traffic, and referral traffic. Because there is no per-click cost, organic traffic is often cited as a high-return long-term channel, though it requires sustained investment in content quality and link building to grow.
Indexing and technical terms
Crawling
Crawling is the automated process by which search engine bots follow hyperlinks to discover and re-examine web pages. How frequently a site is crawled depends on its authority, the rate at which its content changes, and how many external links point to it. A newly submitted directory listing can serve as an additional crawl path, potentially accelerating the discovery of a new page.
Indexing
Indexing is what happens after crawling: the search engine processes and stores page content so it can appear in search results. A page must be indexed before it can rank for any query. Submission to directories can aid indexing indirectly by creating more inbound links that crawlers follow, though the most reliable way to request indexing is via Google Search Console or an XML sitemap.
XML sitemap
An XML sitemap is a structured file, usually served at /sitemap.xml, that lists the URLs on a website along with optional metadata such as last-modified date. Submitting a sitemap to Google Search Console and Bing Webmaster Tools is a direct way to inform search engines which pages exist and should be considered for indexing. Sitemaps do not guarantee indexing, but they reduce the chance that pages go undiscovered.
