The Intrepid Glossary of Advanced SEO Terms

Welcome to Intrepid Digital’s glossary of advanced SEO terms. From A to Z, we’ve defined the most commonly used (and often misunderstood) terms, and we’ve provided reasoning for why that term matters. Here’s to a better understanding of Technical SEO and to implementing the choice tactics below to improve your site’s rankings.

Table of Contents

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200 Status Code

What it is: A 200 status code indicates that the page is accessible and no errors occurred.
Why it matters: Pages with 200 status codes are viewable by bots and users alike. A page needs to both be indexable and have a 200 status code for content to be indexed and ranked.

301 Redirect

What it is: A 301 status code occurs when a URL has been permanently redirected to another URL.
Why it matters: A 301 redirect passes value fully from one URL to another and is a critical component of preserving rankings. This is Google’s preferred method for permanent redirects.

302 Redirect

What it is: A 302 status code occurs when a URL has been temporarily redirected to another URL.
Why it matters: A 302 redirect tells a search engine that the page will return at some point. It does pass ranking signals from the old page to the new. This should be used if the page should not be shown temporarily, for example, a sale page for a particular holiday.

403 Status Code

What it is: A 403 error occurs when a user or bot accesses a link that they do not have the proper credentials to access. The server will not pass on the page content and instead will typically indicate to the user that they do not have permission to view the page.
Why it matters: This is an error code and creates a negative experience for users.

404 Status Code

What it is: A 404 error occurs when a user or a bot accesses a link that is no longer available.
Why it matters: Pages with 404 errors are not indexed. As a result, they can lose value unless redirected to a relevant URL. Users who land on a 404 page may potentially leave the site as a result of the missing page.

5XX Status Code

What it is: A 5XX (500, 502, 503) error code indicates that the server had an error and the page could not be retrieved. 
Why it matters: Pages with persistent 5XX errors can not be accessed and can be dropped from the index, resulting in lost rankings.


Anchor Text

What it is: Anchor text is text contained within an <a href=> link that connects a link to another page. 
Why it matters: Anchor text can be used to pass information on to users and search engines about a link and its destination. Additionally, anchor text from backlinks can help with ranking for the terms contained within the anchor text.

Alt Text

What it is: Alt text (short for “alternative text) provides information about images that Google can then parse. It also is an important accessibility component and helps screen readers determine image content.
Why it matters: Alt text allows Google to better understand what the image is about and can help with ranking (both for ranking the image in image results and for ranking the page that it’s on). It also enables users who use screen readers to understand the image.


What it is: A backlink is a link from one external website to your site. 
Why it matters: Backlinks are seen by Google as sort of a “vote” to the site. If enough quality sites link to a particular site, this lends authority to the page, which can help with ranking.

<Body> Tag

What it is: The <body> tag is an HTML container that contains all primary HTML elements. It contains items such as paragraph tags (<p>), header tags (<h1>, <h2> etc.,) and links that contain anchor text (<a href=””> Link Text</a>) within content. 
Why it matters: A <body> tag is a critical component of HTML and is required for a proper website HTML structure. All content that you want users to be able to see should exist in this tag.

Bot (aka Crawler or Searchbot)

What it is: Search engines use bots to crawl websites in order to identify and process URLs.
Why it matters: Search engine bots are what powers a search engine. Ensuring search engines bots can crawl all important URLs is a critical step to making sure your website URLs can be indexed and ranked.

Blocked Resource

What it is: A blocked resource occurs when a resource file (JavaScript, CSS, Images, etc.) is blocked from being crawled as a result of a robots.txt disallow.
Why it matters: While some resources can be blocked, if the resource is critical to loading page content or mobile-friendly styling, it can result in bots being unable to render and identify content and styles. This can result in lost rankings.


Canonical Element

What it is:  A canonical element <link rel=”canonical” href=”” /> is used to tell search engines what the primary URL for a page is. A canonical tag is seen as a hint to search engines, and they may ignore it if other signals (links, sitemaps etc.) run counter to it.
Why it matters: Canonical tags are used to handle duplicate content and help with content syndication. They indicate which URL is the primary URL that should be ranked.

Canonicalized URL

What it is: A canonicalized URL refers to a URL that has a canonical tag set to another URL.
Why it matters: If the canonical tag on a canonicalized URL is accepted, search engines will pass any value the canonicalized URL has to the canonical (Primary) URL. A canonicalized URL will not rank unless other signals run counter to the canonical tag. See Canonical element.

Core Web Vitals

What it is: Core Web Vitals refers to a set of performance metrics devised by Google and based on three metrics measured by actual user data: LCP (Largest Contentful Paint), INP (Interaction to Next Paint), and CLS (Cumulative Layout Shift).
Why it matters: Google uses page speed (performance) as a ranking signal, and Core Web Vitals are specific metrics that impact page speed. The better scores a website achieves for Core Web Vitals, the better chance of ranking against other similar pages (all other things being equal).

Crawl Budget

What it is: Crawl budget refers to the time and resources Google is willing to spend crawling your site with its bots. Crawl budget is based on multiple factors, including site health, content volume and quality, popularity, and how often content is refreshed. 
Why it matters: Optimizing a site’s crawl budget is crucial for large enterprise sites or medium sites that change frequently. It’s important to monitor how Google is crawling your site and where it is spending its time in order to make sure that you are getting the most out of your crawl budget—so that your most important pages are crawled and subsequently indexed. (See also Robots.txt and XML sitemap for more on how to optimize your crawl budget.)

Crawl Depth

What it is: Crawl depth is how far from the root domain a page resides. This is determined by how many clicks it would take a user to access the page.
Why it matters: Pages with a high crawl depth may lose out on link equity and can also be hard for users to find.

Crawler → see Bot


What it is: Crawling refers to the process a bot uses to process a site, going from link to link and storing the data and relationships for processing. 
Why it matters: Bots need to crawl a site in order to find links and identify and render content. This allows a search engine to identify which URLs are available for indexing.


What it is: Cascading Style Sheets (CSS) contain code that dictates how a site looks. They are a critical component for mobile devices as they tell the device how the content should be displayed.
Why it matters: CSS determines what a website looks like. If the CSS on a page is blocked, it can lead to an unstyled site that is hard to process and read. This can also prevent mobile devices from viewing a site in a format that works for them, resulting in an unfriendly mobile experience for users.

CTR (Click-Through-Rate)

What it is: CTR is a metric that measures how often users click on your URL compared to how often the URL is seen. CTR is found by dividing clicks by impressions. The higher the CTR, the more effective your content, whether that is a search result, a Google ad, or an email. You’ll find this metric in Google Search Console and Google Ads, among other tools.
Why it matters: The higher your CTR, the more traffic you receive, so it’s important to monitor. CTR within search results can be improved by creating enticing titles & meta descriptions and utilizing relevant structured data to capture rich results—causing users to select your result over others.


Duplicate Pages

What it is: Duplicate pages occur when 2 or more URLs share the same content.
Why it matters: Duplicate pages can eat up crawl budget if enough of them exist. Additionally, if a canonical tag is not present, search engines may have difficulty ranking the correct page.



Faceted Navigation

What it is: Faceted Menus are often used on e-commerce websites to provide an easy way for users to filter through products to find what they are looking for.
Why it matters: Faceted menu navigation is a robust way to filter through URLs. The URLs generated by faceted menu navigation need to be handled in a specific way to make sure that they do not result in duplicate or infinite pages.


<Head> Tag

What it is: A <head> tag is an HTML element that contains all meta, Open Graph, hreflang and canonical data. Data such as scripts and stylesheets can also be contained in the head.
Why it matters: <head> tags are the only HTML location that can contain canonicals, meta tags, open graph tags and href lang tags. If these tags are found outside of the <head> tag (also known as a broken <head>), they will not be processed by bots, resulting in potential indexing and content issues.

Heading Tags (aka Header Tags or Header/Heading Elements)

What it is: Heading tags refer to HTML elements H1-H6, which help structure a page’s content.
Why it matters: Heading tags help bots and users understand the structure of the content. H1 tags are especially important as they are an on-page ranking factor that search engines use to determine content importance and ranking. These are also used by assistive devices to indicate levels of a page to users with certain disabilities, such as visual disabilities.

Head Terms → See Keywords

What it is: Head terms are broad keywords used to target queries that are high in search volume. They are used in combination with long-tail keywords to establish the intent of a page and drive the content used on the page. 
Why it matters: Establishing head terms is an important step in keyword research to determine the prioritization of topics for a particular page. 


What it is: Hreflang tags () are used to indicate that a URL exists in a different language and optionally a different region.
Why it matters: Hreflang tags are critical for search engines. They can be used to help search engines understand that content exists in a different language/region that may be better suited to a given user. For example, a user in Germany may be better served by a page that was targeted to Germany/German over a page that was targeted to the US.

HTML Sitemap

What it is: An HTML sitemap is a page that contains a list of all URLs in a structured format.
Why it matters: HTML sitemaps can help users and search engines find and access URLs.

HTTP Status Code

What it is: When visiting a page, a server provides an HTTP Status Code. These codes indicate the state of the page.
Why it matters: HTTP Status codes can be used to diagnose page issues and should be monitored to ensure that pages are properly handled.



What it is: Indexation refers to the process a search engine goes through to determine if a page should be included in search results. When pages that were previously indexed are removed from the index, it is referred to as deindexation.
Why it matters: A page needs to be indexed in order to be ranked, making indexation critical. If a URL should not be indexed, there are meta robots directives that give search engines strong signals to drop the page from a search engine index.

What it is: Internal links refer to links on a website that point to any other part of the website.
Why it matters: Internal links allow bots and users to easily traverse the site.



What it is: JavaScript is a popular programming language that websites use to provide features. React, Angular and Next are common JavaScript frameworks that are in use today.
Why it matters: While very popular and feature-rich, JavaScript can result in large file sizes and rendering issues if not properly configured. JavaScript websites should be thoroughly reviewed to make sure search engines can fully process and render the content.


What it is: JSON-LD is a data format that provides information in an easily readable format. It is often used with Next.JS websites and for structured data.
Why it matters: JSON-LD is Google’s preferred format for structured data and is easily readable by users and bots alike.



What it is: Keywords refer to the terms people use when entering a search in a search engine. They also refer to the terms your organization is targeting in ads or on your site’s pages.
Why it matters: Optimizing for keywords is one aspect of on-page SEO. Keyword rankings can be tracked so that you can monitor the performance of important terms that people are using to find your site. Traffic that is generated through certain keywords can be tracked and monitored as you optimize.


Lazy Loading

What it is: Lazy loading refers to the process of only loading images and video when they come into the viewport on someone’s screen.
Why it matters: Lazy loading can help speed up site load times as a user does not need to load images outside of their viewport until they scroll to them. This results in an overall faster experience. Note that lazy loading should not be used for images in the viewport, as this can delay the Largest Contentful Paint, one of Google’s Core Web Vitals.

What it is:  Link equity, also known as link juice, is the value of a page that can be passed from one page to another through linking. 
Why it matters: A proper internal linking structure can help provide link equity between pages, resulting in potential higher rankings. 

Log File Analysis

What it is: Log File Analysis is the process of reviewing server logs to identify the ways in which  search engine bots crawl a site. Details include how often pages are visited, when they are visited, status codes received upon visiting, and more.
Why it matters: Log File Analysis plays an important role in understanding exactly how search engine bots interact with the site. Reviewing logs can play an important role in understanding problems such as: how often server errors occur, whether or not pages are crawled by a search engine bot, or whether a bot spends an excessive amount of time in specific sections of the site.


Meta Robots Directives

What it is: Meta robots directives (aka meta robots tags) are sometimes used to signal to search engines whether to index a page in search engine results.
Why it matters: Meta robots directives allow you to provide information to Google about pages and content that you want (or don’t want) surfaced in search results, or in search features such as rich snippets.

Mobile-First Indexing

What it is: The primary way in which Google crawls and indexes a given site is via mobile experience rather than desktop. 
Why it matters: Given that Google uses the mobile experience for crawling and indexing, it is important for your site to have a good mobile experience.

Mobile Friendliness

What it is: Mobile-friendly pages are designed to be easy to use on mobile devices, meaning they provide a responsive user experience by adapting all page elements to smaller screens, use touch input, and use various other mobile-specific functionalities. 
Why it matters: Mobile friendliness is important for SEO because Google uses mobile-first indexing and an increasing number of people are using mobile devices to access the internet.


What it is:  Navigation is the process where users and search bots move from page to page on a website. 
Why it matters: A solid navigational structure helps visitors and search engine bots to move easily from one resource to another in order to access, read, understand, and index content.


Off-Page SEO

What it is: Off-Page SEO refers to SEO activities done outside the website to increase its visibility, generally through the acquisition of qualified backlinks.
Why it matters: Being quoted and linked from other domains in a qualified way may enhance your domain relevance and therefore your overall SEO performance.

On-Page SEO

What it is: On-page SEO refers to the application of optimized content, technical guidelines, and structural framework to a particular page in order to optimize it for search.
Why it matters: Google and other search engines use many different factors to evaluate a webpage. Providing these elements and signals is the minimum required in order to be eligible for better visibility, while further optimizations in the visible content and the HTML code should be considered.

Orphan Page (aka Orphan URL)

What it is: An orphan page is one that is live on your site, but not connected or linked from any other pages on your site. People and search engine bots can see them, but they are ‘orphaned’.
Why it matters: An orphan page may still compete with close/duplicate content on the SERP, but any indexable orphan pages should be linked from the website or removed.


Page Speed

What it is: Page speed is the loading time of a web page. 
Why it matters: Page speed is important because fast-loading pages improve the user experience. Page speed is a Google ranking factor.

Parameter URL

What it is: A parameter URL is a feature that enables user behavior tracking based on how they interact with the website.
Why it matters: If not handled correctly, URL parameters may create duplicate content or become a black hole of numerous URL variations—leading to the creation of many pages without any control over the crawl or indexation.



What it is: Rendering is a process where search engine bots, after discovering and crawling your web pages, run your code and interpret it to read the content on the page. 
Why it matters: If search engine bots cannot render your content properly, it means the content (or at least part of it) is not accessible to search engines, potentially impacting your ranking or the indexation of the page.

Redirects → See 301 Redirect

What it is: Redirects move visitors (and search engine bots) from URL A to URL B automatically. The most common redirects are 301 redirects (permanent). On some occasions, 302 (temporary) redirects are more suitable. JavaScript redirects and meta refresh redirects are sometimes used as well, but they are not HTTP status codes and are not recommended for SEO purposes. 
Why it matters: For indexation and ranking purposes, it’s critical to properly redirect URLs and let Google know that some pages have been migrated to new URLs. This best practice reduces the possible loss of traffic and ranking. It’s also important to use 301 redirects whenever possible rather than Javascript or meta refresh redirects, which may not always be picked up by Google.

Responsive Design

What it is: Responsive design is a web design approach where flexible layouts provide a quality user experience regardless of the device used.
Why it matters: The user experience for search bots and users should be equally satisfying from any device used to access your website. Content should be the same regardless of the device (the way of organizing them may vary naturally). Responsive design is now the standard for all web pages.

Rich Snippets (aka Rich Results)

What it is: Features that appear in Google’s SERPs (search engine results), including Recipe results, Video results, or FAQ results. Using structured data in specific ways on your site may help achieve rich snippets. 
Why it matters: A rich snippet may include more data for the potential visitor. It often shows toward the top of the SERP and can therefore impact CTR.

Robots.txt File

What it is: A robots.txt file provides rules for search engine crawlers that indicate which URLs a crawler should crawl on your site and which URLs it is blocked from crawling. It is a plain text file that is placed in the root directory of a website.
Why it matters: With trillions of webpages to visit, it’s helpful to guide search engine bots by telling them what they should and should not crawl. This allows them to prioritize their focus on critical pages of your website and not spend crawl budget on pages you don’t want to be crawled, such as gated pages, pages with sensitive information, or urls that are generated from a filtering function. While these pages definitely serve UX functions, they may not need to be crawled.


Searchbot → See Bot

Site Structure

What it is: Site Structure is the skeleton of your website. It defines how pages and documents are connected to each other and how people and search engine bots should find them.
Why it matters: From a search engine perspective, the number and location of paths connecting content help determine their importance. Flat site structure is problematic; trying to tell Google everything is important means nothing is important. And site structure with many deep levels may also be problematic.

Structured Data (aka Vocabulary)

What it is: Structured data (also known as schema markup, or markup)  is JSON-LD code that you can add to your web pages to help provide search engines with additional information for understanding a website. 
Why it matters: Certain structured data types can help enhance a site’s visibility in search engine results.

Soft 404

What it is: A Soft 404 is a web page that is considered an error page by search engine bots but does not return a 404 HTTP status code. A soft 404 indicates that something is wrong with the way search engine bots perceive the page. 
Why it matters: For example, Google flags product pages that are out of stock as soft 404s because they no longer meet a user’s expectations. Another example is a page that returns no results on the page, which Google may also flag as a soft 404. These pages should be reviewed and addressed in order to make sure important pages are not incorrectly flagged as soft 404s.


Technical Site Audit

What it is: This exercise is a thorough evaluation of technical factors that affect a website’s performance in search results. 
Why it matters: A technical site audit provides visibility into a site’s technical health and provides prioritized, actionable recommendations for implementing fixes. It is often the first step to vast improvements in a site’s health.


User Experience (aka UX)

What it is: UX is the interaction between a user and a product or service—in this case, with a website and its assets. User experience is the industry term for providing a good page experience to users.
Why it matters: Keeping UX in mind with any new pages or website designs is critical for creating a positive experience and helping users find what they need on your site. In addition, user experience plays a role in a ranking factor that Google calls Page Experience.


Web Accessibility

What it is: The concept of making websites accessible for all users, including those with disabilities. 
Why it matters: Although not a direct ranking factor, an accessible site means that the user experience is positive for all users regardless of disability, a factor that is important to Google.


XML Sitemap

What it is: An XML sitemap is a file that can improve the crawlability of a website. It lists the pages on your site while providing hierarchy information and data on when a page was last modified. This helps search engines understand your site’s structure and content as it crawls. The XML sitemap is one of the first things that crawlers visit because the robots.txt links directly to the XML sitemap.
Why it matters: An XML sitemap allows you to prioritize which pages you want a search engine to find and index, which helps manage crawl budget. While there is no guarantee that a search engine will index pages in your sitemap, it is a helpful hint that can aid in indexing.

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