Reference
Web design glossary
Plain-English definitions of 167 Bootstrap 5, HTML, CSS, performance and SEO terms. Search for a term or jump to a letter.
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301 Redirect
301 Redirect is an HTTP status code (defined in RFC 9110) that tells browsers and search engine crawlers a requested URL has permanently moved to a new location, supplied in the Location response header.
404 Error
A 404 error is an HTTP response status code defined in RFC 9110 (the HTTP Semantics specification) indicating that the server successfully received and processed a request but could not locate the requested resource at the given URL.
A
A/B Testing
A/B testing (also called split testing) is a controlled experiment where two versions of a web page, email, or element (A and B) are shown to different segments of users simultaneously to determine which version drives better results.
Above the Fold
Above the fold refers to the portion of a web page visible without scrolling. The term originates from newspaper printing, the top half of a folded newspaper that faces up on a newsstand.
Alt Text
Alt text (alternative text) is a string attribute added to the HTML img element via the alt attribute, providing a textual description of an image for contexts where the image cannot be rendered or perceived.
Anchor Text
Anchor text is the visible, clickable text within an HTML hyperlink, defined between the opening and closing tags of the anchor element. It serves a dual purpose: communicating link destination context to human readers and providing semantic signals to search engine crawlers that influence how the linked page is indexed and ranked.
ARIA Labels
2 specification that provide text descriptions for HTML elements when native semantics or visible text are insufficient for assistive technologies.
B
Backlink
A backlink is an inbound hyperlink from one website pointing to a page on a different domain, serving as a third-party citation that search engines use to assess a page's authority and relevance.
Bootstrap 5
Bootstrap 5 is a free, open-source CSS and JavaScript framework used to build responsive, mobile-first websites. Released in 2021, it provides a comprehensive library of pre-built components, a 12-column grid system, and utility classes that help developers create professional web layouts quickly and consistently.
Bootstrap 5 Accordion
The Bootstrap 5 accordion is a component that stacks collapsible panels vertically, each with a clickable header that shows or hides its content, and by default opening one panel closes the others.
Bootstrap 5 Border Utilities
Bootstrap 5 border utilities are CSS classes that add, remove, colour, size and round borders on any element directly in the HTML. rounded cover the most common border styles without custom CSS.
Bootstrap 5 Breakpoints
Bootstrap 5 breakpoints are predefined CSS media query thresholds, xs (0px), sm (576px), md (768px), lg (992px), xl (1200px), and xxl (1400px), that define the viewport widths at which a layout adapts to different screen sizes.
Bootstrap 5 Card Component
card class, that can hold an image, header, body text, links, list groups and a footer in any combination. Cards are used for product listings, blog post previews, team profiles, pricing plans and feature grids, and because they are built with flexbox they fit neatly into Bootstrap's responsive grid.
Bootstrap 5 Carousel
The Bootstrap 5 Carousel is a slideshow component built on CSS transitions and the Bootstrap JavaScript plugin system, enabling cyclic display of images, text, or mixed content within a single responsive container.
Bootstrap 5 Color Utilities
Bootstrap 5 Color Utilities are a set of CSS utility classes that apply foreground text colors, background colors, and gradient overlays to HTML elements using a predefined design token system mapped to CSS custom properties (variables).
Bootstrap 5 Display Headings
display-6) that render oversized, visually dominant typographic elements designed for hero sections, landing pages, and high-impact headings, distinct from standard h1 to h6 elements in that they prioritize visual weight over semantic hierarchy.
Bootstrap 5 Display Utilities
Bootstrap 5 Display Utilities are a set of responsive CSS classes that control the CSS display property of any HTML element across six breakpoints (xs, sm, md, lg, xl, xxl), using the naming convention d-{value} or d-{breakpoint}-{value}.
Bootstrap 5 Flexbox Utilities
Bootstrap 5 Flexbox Utilities are a set of CSS utility classes that expose the CSS Flexible Box Layout Module (Flexbox) specification directly in HTML markup, eliminating the need to write custom CSS for alignment, direction, wrapping, and spacing of flex containers and items.
Bootstrap 5 Font Size Classes
Bootstrap 5 font size utility classes are a set of predefined CSS classes (fs-1 through fs-6) that apply responsive, scale-aware font sizes derived from Bootstrap's internal $font-sizes Sass map, which maps each class to a corresponding rem-based value.
Bootstrap 5 Font Weight Utilities
fw-lighter, which are relative to the parent element. They are used to create emphasis and hierarchy in headings, labels, prices and body text.
Bootstrap 5 Grid System
The Bootstrap 5 Grid System is a responsive, mobile-first layout framework built on CSS Flexbox that divides a page into 12 equal columns across six breakpoint tiers (xs, sm, md, lg, xl, xxl).
Bootstrap 5 Modal Component
The Bootstrap 5 Modal component is a layered dialog overlay system built on top of the HTML <dialog>-inspired pattern, using custom JavaScript and CSS to render accessible, focus-trapped popup windows without relying on the native browser dialog API.
Bootstrap 5 Navbar Component
The Bootstrap 5 Navbar component is a responsive navigation header built on Flexbox that provides a collapsible, accessible navigation bar through a combination of utility classes, JavaScript toggling, and ARIA attributes.
Bootstrap 5 Overflow Utilities
Bootstrap 5 Overflow Utilities are a set of CSS helper classes that control how content behaves when it exceeds the boundaries of its container, mapping directly to the CSS overflow property values: auto, hidden, visible, and scroll.
Bootstrap 5 Position Utilities
Bootstrap 5 Position Utilities are a set of CSS helper classes that control the CSS position property and related offset properties (top, bottom, start, end) on HTML elements, enabling developers to place elements as static, relative, absolute, fixed, or sticky without writing custom CSS.
Bootstrap 5 Shadow Utilities
shadow-none to remove it. They add depth to cards, buttons, navbars and images directly in the HTML without custom CSS.
Bootstrap 5 Sizing Utilities
Bootstrap 5 Sizing Utilities are a set of CSS helper classes that control the width and height of elements using predefined percentage-based and viewport-relative values, without writing custom CSS.
Bootstrap 5 Spacing Utilities
Bootstrap 5 Spacing Utilities are a set of CSS utility classes that apply margin and padding values to elements using a consistent scale derived from a base spacer variable (default: 1rem).
Bootstrap 5 Table Classes
table-sm change their appearance. table-responsive lets it scroll horizontally on small screens instead of breaking the layout.
Bootstrap 5 Tabs and Nav Pills
nav class system, used to organize content into selectable panels without a full page reload. tab-pane content blocks via Bootstrap's JavaScript Tab plugin.
Bootstrap 5 Text Utilities
text-decoration-none. text-md-start, so text can be centred on phones and aligned to the start on larger screens.
Bootstrap 5 Typography
Bootstrap 5 Typography is the typographic foundation built into Bootstrap 5's CSS framework, providing a default type scale, heading normalization, display classes, lead text, blockquote components, and utility classes all built on native browser font stacks and CSS custom properties (variables).
Bootstrap Grid
The Bootstrap grid system is a responsive, 12-column layout framework built on CSS flexbox. It uses a series of containers, rows, and column classes to let developers build complex responsive layouts without writing custom CSS.
Bounce Rate
Bounce rate is the percentage of sessions in which a user lands on a page and exits without triggering any additional requests to the analytics server, no clicks, no navigation, no tracked interactions.
Breadcrumb Navigation
Breadcrumb navigation is a secondary navigation pattern that displays a user's current location within a site's hierarchical structure as a linear trail of links, typically formatted as 'Home > Category > Subcategory > Current Page'.
Breadcrumbs
g. Home > Blog > Web Design > What Is Responsive Design. Named after the Hansel and Gretel fairy tale, breadcrumbs help users understand site structure, navigate back to parent sections, and provide search engines with hierarchical context for pages.
Browser Caching
Browser caching is a mechanism by which a web browser stores local copies of static assets, HTML, CSS, JavaScript, images, and fonts, so subsequent page visits can load those resources from disk rather than re-fetching them from the origin server.
C
Call to Action (CTA)
A call to action (CTA) is a design element, typically a button or link, that prompts users to take a specific, desired action. CTAs are the conversion levers of any web page.
Canonical URL
A canonical URL is the preferred version of a web page URL that you designate as the 'master' version when multiple URLs show the same or very similar content.
Canvas Template
Canvas Template is a premium Bootstrap 5 HTML template created by SemiColonWeb, available on ThemeForest (Envato Market). With 75,000+ sales and a decade of active development, it is the most popular Bootstrap 5 HTML template in the world.
CDN (Content Delivery Network)
A Content Delivery Network (CDN) is a geographically distributed network of servers that caches and delivers web content (images, CSS, JS, video) from locations close to the end user.
Click-Through Rate (CTR)
Click-through rate (CTR) is the percentage of people who click a link after seeing it, calculated as clicks divided by impressions, multiplied by 100.
Colour Contrast
Colour contrast in web design refers to the difference in luminance between a foreground colour (typically text) and its background colour.
Conversion Rate
Conversion rate is the percentage of website visitors who complete a desired action, signing up, purchasing, downloading, or contacting. It's calculated as: (Number of Conversions ÷ Total Visitors) × 100.
Conversion Rate Optimisation (CRO)
Conversion Rate Optimisation (CRO) is the systematic process of increasing the percentage of website visitors who complete a desired action, such as submitting a form, making a purchase, or clicking a CTA, by analysing user behaviour and iteratively improving page elements through data-driven testing.
Core Web Vitals
Core Web Vitals are a set of real-world performance metrics defined by Google that measure the user experience of a web page, specifically loading performance, interactivity, and visual stability.
Crawl Budget
Crawl Budget is the number of URLs a search engine bot, such as Googlebot, will crawl and index on a given website within a set timeframe, determined by two factors: crawl rate limit (how fast the bot can crawl without overloading the server) and crawl demand (how much Google prioritizes crawling your pages based on popularity and freshness).
CSS Animation
CSS animation is a native browser feature that lets developers create smooth visual transitions and motion effects on HTML elements without relying on JavaScript.
CSS border-radius Property
The CSS border-radius property rounds the corners of an element's outer border edge by defining the radii of elliptical or circular corner curves, as specified in the CSS Backgrounds and Borders Module Level 3 (W3C).
CSS Box Model
The CSS Box Model is the foundational layout algorithm defined in the CSS2 specification (and refined in CSS3) that treats every HTML element as a rectangular box composed of four nested layers: content, padding, border, and margin.
CSS box-shadow Property
The CSS box-shadow property adds one or more shadow effects to an element's bounding box, rendered outside the element's normal document flow without affecting layout.
CSS Custom Properties (Variables)
CSS custom properties, commonly called CSS variables, are entities defined by CSS authors that contain specific values to be reused throughout a document.
CSS Display Property
The CSS display property determines how an element generates a box in the document layout flow, controlling both the element's outer display type (how it participates in its parent's formatting context) and its inner display type (how it establishes a formatting context for its children).
CSS Flexbox
CSS Flexbox (Flexible Box Layout) is a CSS layout model that makes it easy to align and distribute space among items in a container, even when their sizes are unknown or dynamic.
CSS Framework
A CSS framework is a pre-built library of CSS (and often JavaScript) that provides a foundation for web development, including a grid system, pre-styled components, utility classes, and design conventions.
CSS Gradient Background
A CSS gradient background is a programmatically generated image created entirely in CSS using functions like linear-gradient(), radial-gradient(), or conic-gradient() to produce smooth color transitions without any third-party image files.
CSS Grid
CSS Grid Layout is a two-dimensional layout system that lets you create complex web layouts by defining both rows and columns simultaneously.
CSS Media Query
A CSS media query is a conditional rule defined in the CSS3 Media Queries specification (W3C) that applies styles only when specific device or viewport characteristics, such as screen width, resolution, orientation, or color depth, match defined criteria.
CSS Overflow Property
The CSS overflow property controls how a browser renders content that exceeds the boundaries of its containing block element, with values including visible, hidden, scroll, clip, and auto.
CSS Position Property
The CSS position property controls how an element is placed in the document flow and how it establishes a positioning context for child elements.
CSS Position Sticky
CSS Position Sticky is a hybrid positioning model defined in the CSS Positioning Level 3 specification that allows an element to behave as position: relative within its normal document flow until a defined scroll threshold is crossed, at which point it switches to position: fixed-like behavior within its containing block.
CSS Pseudo-Classes
CSS pseudo-classes are keywords added to a selector that specify a special state of the selected element, defined in the CSS Selectors specification (currently Level 4).
CSS Specificity
CSS Specificity is the algorithm browsers use to determine which CSS rule takes precedence when multiple conflicting declarations target the same element.
CSS text-shadow Property
The CSS text-shadow property applies one or more shadow effects to text characters, accepting a comma-separated list of shadows each defined by horizontal offset, vertical offset, optional blur radius, and color.
CSS Transform
CSS Transform is a CSS module that allows elements to be visually repositioned, scaled, rotated, or skewed in 2D or 3D space without affecting document flow or triggering layout recalculation.
CSS3
CSS3 is the third major iteration of the Cascading Style Sheets specification, introducing modular sub-specifications that enable advanced visual effects, responsive layouts, animations, and custom properties directly in the browser without JavaScript or image assets.
Cumulative Layout Shift (CLS)
Cumulative Layout Shift (CLS) is a Core Web Vital metric developed by Google that quantifies the visual stability of a webpage by measuring the sum of all unexpected layout shift scores occurring during the page's entire lifespan.
D
Dark Mode
Dark mode is a display setting that uses a dark (typically near-black) background with light-coloured text, replacing the traditional light background with dark text.
Defer vs Async Scripts
The defer and async attributes on HTML <script> tags control how the browser fetches and executes JavaScript relative to HTML parsing. defer downloads the script in parallel with parsing and executes it only after the DOM is fully parsed, preserving execution order.
Domain Authority
Domain Authority (DA) is a logarithmic scoring metric developed by Moz, scaled from 1 to 100, that predicts how likely a domain is to rank competitively in search engine results pages based on the quantity and quality of inbound links pointing to it.
Domain Name
com) that maps to one or more IP addresses through the Domain Name System (DNS), enabling users to reach web servers without memorizing numeric addresses.
Duplicate Content
Duplicate content refers to substantively identical or very similar content that appears at multiple distinct URLs, either within the same domain or across different domains.
Dwell Time
Dwell time is the duration a user spends on a webpage after clicking through from a search engine results page (SERP) before returning to those results, distinct from session duration or time-on-page as measured by analytics tools.
E
E-E-A-T
E-E-A-T stands for Experience, Expertise, Authoritativeness, and Trustworthiness, a framework Google's Search Quality Rater Guidelines use to evaluate the credibility and quality of web content.
Entity SEO
Entity SEO is the practice of optimizing web content around semantically defined entities, people, places, organizations, products, concepts, and events, rather than isolated keywords, enabling search engines like Google to build a knowledge-graph understanding of what a page is 'about' at a conceptual level.
ETags
ETags (entity tags) are HTTP response headers that give a specific version of a file a unique identifier, such as a hash of its contents. When the file changes, its ETag changes, so browsers and CDNs can ask the server whether their cached copy is still current and receive a small 304 Not Modified response instead of downloading the whole file again.
F
F-Pattern Layout
The F-Pattern Layout is a web design approach modeled after eye-tracking research showing that users scan web pages in a pattern resembling the letter 'F', reading horizontally across the top, then scanning down the left edge with shorter horizontal movements.
Faceted Navigation SEO
Faceted navigation SEO is the practice of controlling how search engine crawlers interact with filter-generated URLs on e-commerce and catalog sites, where combinations of attributes like color, size, price, and brand produce thousands of near-duplicate pages that dilute crawl budget, fragment link equity, and trigger Googlebot traps.
Favicon
A favicon (short for 'favourite icon') is the small icon associated with a website, displayed in browser tabs, bookmark lists, browser history, address bars, and Google search results.
favicon.ico
ico is a small square icon file, traditionally 16×16 or 32×32 pixels, that browsers display in tabs, bookmarks, browser history, and address bars to visually identify a website.
Financial Website Design
Financial website design is the practice of planning and building websites for banks, credit unions, financial advisers, accountants, insurers and fintech companies, where visitors are deciding whether to trust a business with their money.
Flexbox vs CSS Grid
Flexbox (CSS Flexible Box Layout) and CSS Grid are two distinct CSS layout modules that solve different dimensional problems: Flexbox is a one-dimensional system designed for arranging items along a single axis (row or column), while CSS Grid is a two-dimensional system that controls layout across both rows and columns simultaneously.
Font-display: swap
Font-display: swap is a CSS @font-face descriptor defined in the CSS Fonts Level 4 specification that instructs the browser to immediately render text using a fallback system font while the custom web font downloads, then swap in the custom font once it's available.
Front-End Development
Front-end development is the discipline of building the client-side (user-facing) portion of websites and web applications, everything users see and interact with in their browser.
G
Git
Git is a distributed version control system (DVCS) created by Linus Torvalds in 2005 that tracks changes to files over time using a directed acyclic graph (DAG) of commit objects.
Google Analytics
Google Analytics (GA) is a free web analytics service provided by Google that tracks and reports website traffic, user behaviour, and conversions.
Google Search Console
Google Search Console (GSC) is a free web service provided by Google that lets webmasters monitor how Googlebot crawls, indexes, and ranks their site's pages within Google Search.
Gzip Compression
Gzip compression is a way of shrinking text-based files such as HTML, CSS, JavaScript, JSON and SVG on the server before they are sent to the browser, which then decompresses them automatically.
H
Healthcare Website Design
1 AA minimum), HIPAA-related web guidelines, and medical content credibility requirements. It encompasses trust-signal architecture, compliant form handling for protected health information (PHI), and performance optimization for diverse patient demographics including elderly and low-literacy users.
Hero Section
A hero section is the large, prominent area at the top of a web page, the first thing visitors see when they land on the page, before any scrolling.
Hreflang Tag
">, that tells search engines which language and regional versions of a page exist and which URL suits which audience. It helps Google show each searcher the version in their language or for their country, for example the UK English page to searchers in the UK and the German page to searchers in Germany.
HTML Head Elements
HTML head elements are tags placed within the <head> section of an HTML document that provide metadata, resource links, and configuration directives to browsers and crawlers, none of which render visually on the page.
HTML Template
An HTML template is a pre-written HTML file (or collection of files) that provides a ready-made structure for a web page or website. Rather than coding a page from scratch, developers use HTML templates as a starting point, swapping out text, images, and colours to suit their project while keeping the underlying layout and code structure intact.
HTML5
HTML5 is the fifth and current major version of the HyperText Markup Language, standardized by the W3C and WHATWG, introducing native support for semantic elements, multimedia embedding, offline storage, and APIs like Canvas and WebSockets without requiring third-party plugins.
HTTP vs HTTPS
HTTP (HyperText Transfer Protocol) and HTTPS (HTTP Secure) are the foundational application-layer protocols governing data transfer between web clients and servers, with HTTPS adding a TLS (Transport Layer Security) encryption layer that authenticates the server and encrypts all transmitted data.
HTTP/2 vs HTTP/3
HTTP/2 and HTTP/3 are the two newest major versions of HTTP, the protocol browsers use to request web pages and files. 3 built in that connects faster and copes better with packet loss and network changes.
I
Indexation
Indexation is the process by which a search engine analyses a crawled page and stores it in its index, the database it draws on to show search results.
Interaction to Next Paint (INP)
Interaction to Next Paint (INP) is a Core Web Vital metric that measures the latency between a user's input event (click, tap, or keyboard press) and the next frame the browser paints in response, capturing the worst-case interaction delay across a page's full lifetime.
Internal Linking
Internal linking is the practice of hyperlinking from one page of a website to another page on the same domain. Unlike external links (to other websites), internal links help search engines discover and understand the relationship between pages, distribute link equity (ranking power) from high-authority pages to lower ones, and help users navigate to relevant content.
International SEO
International SEO is the practice of optimizing a website so that search engines can correctly identify which countries and languages you are targeting, serving the right content to the right audience in the right locale.
J
JavaScript
js, on servers). As the third layer of web development, alongside HTML (structure) and CSS (style), JavaScript adds interactivity and dynamic behaviour to web pages: form validation, animated menus, API calls, real-time updates, and complex web applications.
JSON
JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format defined by RFC 8259 and ECMA-404 that represents structured data as human-readable key-value pairs, arrays, and nested objects.
K
Keyword Clustering
Keyword clustering is the practice of grouping semantically related search terms into topic-based sets, then mapping each cluster to a single page or content asset rather than creating separate pages for every individual keyword.
Keyword Difficulty
Keyword difficulty (KD) is a numeric score, typically on a 0-100 scale, that estimates how hard it will be to rank a web page on the first page of Google or other search engines for a given keyword.
Keyword Research
Keyword research is the process of identifying the words and phrases people type into search engines when looking for information, products, or services related to your business.
L
Landing Page
A landing page is a standalone web page designed with a single, focused objective, to convert visitors into leads, customers, or subscribers.
Landing Page Sections
Landing page sections are discrete, full-width structural blocks within a single-page or campaign-focused HTML document, each serving a distinct conversion purpose, such as hero, social proof, features, pricing, or CTA.
Largest Contentful Paint (LCP)
Largest Contentful Paint (LCP) is a Core Web Vital metric defined by the W3C Largest Contentful Paint specification that measures the render time of the largest image, video, or block-level text element visible within the browser viewport.
Law Firm Website Design
Law firm website design is the practice of planning and building websites for solicitors, attorneys and legal practices so that potential clients can quickly understand what the firm handles, judge whether it can be trusted, and request a consultation.
Lazy Loading
Lazy loading is a performance technique that defers the loading of non-critical resources (typically images and iframes) until they are needed, specifically, until they enter or approach the user's viewport as they scroll.
Local SEO
Local SEO is the practice of optimising a business's website and online listings so it appears in location-based searches, such as the Google map pack, Google Maps and "near me" queries.
Long-Tail Keyword
A long-tail keyword is a search query composed of three or more words that targets a specific user intent, typically generating lower search volume but significantly higher conversion rates than broad, single-word terms.
M
Meta Description
A meta description is an HTML element placed in the document's <head> section that provides a concise summary (typically 150-160 characters) of a webpage's content.
Meta Tags
Meta tags are snippets of HTML code placed in the <head> section of a web page that provide metadata, information about the page that isn't displayed visually but is read by search engines, browsers, and social media platforms.
Minification
Minification is the process of removing all unnecessary characters from source code (whitespace, comments, newlines, and redundant semicolons) and optionally renaming variables to shorter identifiers, without changing the code's runtime behavior.
Mobile-First Design
Mobile-first design is a strategy where web design and development begins with the smallest screen (mobile phones) and progressively adds complexity for larger screens (tablets, desktops).
N
Nofollow
Nofollow is an HTML link attribute value (rel='nofollow') that instructs search engine crawlers not to pass PageRank or link equity from the source page to the linked destination.
Noindex
Noindex is a directive that instructs search engine crawlers not to include a specific page in their search index, preventing it from appearing in search results.
npm (Node Package Manager)
js: a command-line tool and a public online registry used to install, share and manage JavaScript packages such as Bootstrap, Sass and build tools.
O
OG Image (Open Graph Image)
me) that designates which image platforms like Facebook, LinkedIn, Twitter/X, Slack, and iMessage should display when a URL is shared as a link preview card.
Open Graph
Open Graph (OG) is a protocol developed by Facebook that enables web pages to become rich objects in social media. By adding Open Graph meta tags to your page's <head>, you control exactly how your page title, description, and image appear when someone shares your URL on Facebook, LinkedIn, Slack, WhatsApp, and other platforms that support the protocol.
Organic Traffic
Organic traffic is the visitors who arrive at a website by clicking an unpaid result in a search engine such as Google, Bing or DuckDuckGo.
P
Page Speed
Page speed refers to how quickly a web page loads and becomes usable for visitors. It's measured by multiple metrics, Time to First Byte (TTFB), First Contentful Paint (FCP), Largest Contentful Paint (LCP), and Time to Interactive (TTI).
People Also Ask
People Also Ask (PAA) is a Google search results feature that shows a box of questions related to the search, each of which expands to reveal a short answer taken from a web page, with a link to that page.
Performance Budget
A performance budget is a set of quantitative limits placed on metrics that affect a website's load time, rendering speed, or resource weight, such as total page size, JavaScript bundle size, Time to Interactive (TTI), or Core Web Vitals scores, that a team commits not to exceed.
Preconnect & DNS Prefetch
Preconnect and DNS Prefetch are HTML resource hint directives that instruct the browser to perform early network setup for third-party origins before any resource from that origin is explicitly requested.
Progressive Web App (PWA)
A Progressive Web App (PWA) is a web application that uses modern browser APIs, primarily Service Workers, the Web App Manifest, and HTTPS, to deliver app-like experiences including offline functionality, push notifications, and home screen installation without requiring distribution through an app store.
R
RankBrain
RankBrain is Google's machine learning-based search ranking component, deployed in 2015, that uses word vector mathematics to interpret ambiguous or never-before-seen queries by mapping them to conceptually similar queries with known results.
Render-Blocking Resources
Render-blocking resources are third-party files, primarily CSS stylesheets and synchronous JavaScript, that the browser must fully download and parse before it can construct the render tree and paint the first pixel to screen.
Responsive Design
Responsive web design (RWD) is an approach to web development where a website's layout and content automatically adapt to fit the screen size and orientation of the device being used.
REST API
REST (Representational State Transfer) API is an architectural style for distributed hypermedia systems, defined by Roy Fielding in his 2000 doctoral dissertation, that uses stateless HTTP methods (GET, POST, PUT, PATCH, DELETE) to expose resources via structured URIs.
Robots.txt
g. txt) that provides instructions to web crawlers about which pages they can and cannot access. It follows the Robots Exclusion Protocol and is the first thing most crawlers check before crawling a site.
S
Sass / SCSS
Sass (Syntactically Awesome Style Sheets) is a CSS preprocessor that extends standard CSS with programming features: variables ($primary: #1abc9c), nesting, mixins (reusable style blocks), functions, and partials (modular file organisation).
Schema Markup
Schema markup (also called structured data) is code added to your web pages, typically as JSON-LD in a <script> tag, that helps search engines understand the meaning and context of your content.
Search Intent
Search intent is the goal behind a search query: what the person actually wants to find, learn or do when they type it. It is usually grouped into four types (informational, navigational, commercial and transactional), and because search engines rank pages that satisfy that goal, matching the type and format of your content to the intent is a prerequisite for ranking.
Search Volume
Search volume is the average number of times a specific keyword or phrase is queried in a search engine within a given time period, typically measured monthly.
Semantic HTML
Semantic HTML is the practice of using HTML elements that convey meaning about the content they contain, not just visual presentation. Instead of using <div> for everything, semantic HTML uses elements like <header>, <nav>, <main>, <article>, <section>, <aside>, and <footer> to communicate the role of each page region to browsers, search engines, and screen readers.
SEO (Search Engine Optimisation)
SEO (Search Engine Optimisation) is the practice of improving a website's visibility in organic (unpaid) search engine results, primarily Google, which handles over 90% of global search queries.
SERP
A Search Engine Results Page (SERP) is the webpage returned by a search engine in response to a user query, containing a ranked list of organic results, paid advertisements, and rich features such as featured snippets, knowledge panels, local packs, and image carousels.
Single-Page Application (SPA)
A single-page application (SPA) is a web application that loads a single HTML document and dynamically updates content using JavaScript, without reloading the full page.
SSL / HTTPS
SSL (Secure Sockets Layer), now technically its successor TLS (Transport Layer Security), is an encryption protocol that secures the connection between a user's browser and a web server.
Structured Data & Schema Markup
org vocabulary, that describes the content of a page in explicit terms: for example that the page is a Product with a price, an Article with an author and date, or a LocalBusiness with an address.
SVG (Scalable Vector Graphics)
SVG (Scalable Vector Graphics) is an XML-based vector image format standardized by the W3C that describes two-dimensional graphics using geometric primitives such as paths, circles, rectangles, and text nodes rather than a pixel grid.
T
Tailwind CSS
Tailwind CSS is a utility-first CSS framework that provides low-level, single-purpose CSS classes, called utilities, that you compose directly in your HTML to build designs.
Thin Content
Thin content is web content that offers little or no original value to visitors, such as near-empty pages, auto-generated text, doorway pages, scraped or copied material, and affiliate pages that add nothing to product information available elsewhere.
Time to First Byte
Time to First Byte (TTFB) is the time between the browser starting a request for a page and receiving the first byte of the server's response.
Title Tag
A title tag is an HTML element placed within the <head> section of a webpage that specifies the official name or title of that page, rendered in the browser tab and used as the default clickable headline in search engine results pages (SERPs).
Topical Authority
Topical authority is a search engine's measure of how comprehensively and accurately a website covers a specific subject domain, determined by the depth, breadth, and semantic relationships between its content.
Twitter Card Meta Tags
Twitter Card meta tags are HTML <meta> elements placed in a page's <head> that instruct Twitter (now X) how to render rich preview cards when a URL is shared, controlling the card type, title, description, image, and associated account.
U
V
Version Control (Git)
Version control is a system that records changes to files over time, allowing you to recall specific versions, see who changed what and when, and collaborate with others without overwriting each other's work.
Viewport Meta Tag
The viewport meta tag is an HTML element placed in the document head that instructs mobile browsers how to scale and size the visible area of a webpage relative to the device screen.
Visual Hierarchy
Visual hierarchy is the deliberate arrangement of design elements, size, color, contrast, spacing, and position, to guide a user's eye through content in a specific, intentional order.
W
Web Accessibility (WCAG)
Web accessibility (often abbreviated a11y) is the practice of designing and building websites that can be used by everyone, including people with visual, auditory, motor, or cognitive disabilities.
Web Deployment
Web deployment is the process of transferring a web application or static site from a local development environment to a production server or hosting infrastructure where end users can access it via the internet.
Web Design
Web design is the process of conceptualising, planning, and creating the visual layout, structure, and user experience of websites. It encompasses graphic design (colour, typography, imagery), UI design (buttons, forms, navigation), information architecture (content organisation), and UX design (user flows, interaction patterns).
Web Fonts
Web fonts are typefaces loaded from third-party sources (remote servers or local hosting) rather than relying on fonts pre-installed on a user's operating system, enabling consistent typography across all devices and browsers.
Web Fonts Optimisation
Web fonts optimisation is the practice of reducing the performance cost of loading custom typefaces by controlling file formats, subsetting character sets, managing render blocking, and tuning browser font-loading behaviour via CSS and resource hints.
Web Hosting
Web hosting is a service that stores your website's files (HTML, CSS, JavaScript, images, databases) on servers connected to the internet, making your site accessible to visitors via a domain name.
Web Typography
Web typography is the practice of selecting, sizing, and styling text on websites to ensure readability, visual hierarchy, and aesthetic quality.
WebP Image Format
WebP is a modern raster image format developed by Google, introduced in 2010, that provides superior lossless and lossy compression for images on the web, delivering files 25 to 34% smaller than comparable JPEG or PNG files at equivalent visual quality.
Website Builder
A website builder is a tool or platform that enables users to create websites without writing code from scratch. Website builders range from hosted drag-and-drop platforms (like Wix or Squarespace) where the site lives on the provider's servers, to AI-powered code generators (like Canvas Builder) that produce downloadable HTML files you host anywhere.
White Space in Design
White space in design, also called negative space, is the empty area between and around elements on a page, such as margins, padding, the gaps between paragraphs and the space between lines of text.
Wireframe
A wireframe is a low-fidelity, schematic representation of a web page or app screen that shows the structure and layout without visual design details.
WordPress
WordPress is a free, open-source content management system (CMS) that powers approximately 43% of all websites on the internet. Originally a blogging platform (launched 2003), WordPress has evolved into a general-purpose CMS and website builder through its extensive plugin ecosystem.
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Put the theory to work
Describe any page in plain English and Canvas Builder generates production-ready Bootstrap 5 HTML in about 3 minutes.