// Glossary

The plain-English web design glossary.

Every term a UK business owner runs into when commissioning a website — design, SEO, performance and hosting — explained without jargon. Skim the categories or Ctrl-F the term you're stuck on.

DesignDevelopmentSEOPerformanceContentAnalyticsHosting
// Design

Design terms

Above the fold#above-the-fold
The part of a page visible before scrolling.
Above the fold is what a visitor sees on a device before scrolling. On a service-business homepage this is where your headline, proof and primary CTA live — get those three right and the rest of the page has room to breathe.
Whitespace#whitespace
Empty space between elements — the negative space of a layout.
Whitespace isn't wasted space. It's how a design tells a reader where to look first. Editorial magazines have relied on it for a century; the best service-business websites use it to slow scroll and lift focus onto the CTA.
Design system#design-system
A reusable set of tokens, components and rules that make a site consistent.
A design system is the source of truth for a website's colours, typography, spacing and components. It's what stops a site drifting into a Frankenstein of one-off pages after a year of edits — and what makes new sections cheap to add.
Wireframe#wireframe
A low-fidelity blueprint of a page's structure.
A wireframe shows structure without style — where the headline, sections, form and CTA sit — so decisions get made about content and hierarchy before anyone argues about colour.
Mockup#mockup
A high-fidelity static design of a page.
A mockup is a pixel-accurate design of a finished page, usually in Figma. It comes after wireframes and before code — the last place to change layout cheaply.
Responsive design#responsive-design
A layout that adapts to any screen size.
Responsive design uses fluid grids and CSS breakpoints so a single page renders correctly on phone, tablet, laptop and desktop. Since 2015 it's been a Google ranking signal — a mobile-only broken site is a de facto invisible site.
Mobile-first#mobile-first
Designing for the smallest screen before scaling up.
Mobile-first is a design approach where the phone layout is built first and desktop adaptations come later. Over 60% of UK web traffic is mobile — starting with the constraint that matters most avoids desktop-only decisions that break on the device most visitors actually use.
Grid system#grid-system
A vertical column framework that structures layouts.
A grid divides a page into columns (usually 12) so elements line up predictably. Editorial-grade design relies on grid discipline; it's the reason a well-built site feels calm and a cheap template feels twitchy.
Typography scale#typography-scale
A defined set of font sizes used across a site.
A typography scale is the small, deliberate list of text sizes (say H1 48/H2 32/H3 24/body 16) used everywhere. Without one, sites drift into a dozen font sizes and lose visual rhythm.
Accessibility (a11y)#accessibility
Building sites that work for people with disabilities.
Accessibility (sometimes shortened to a11y) means building sites usable by people using screen readers, keyboard-only input, low-vision zoom and other assistive tech. Under the UK Equality Act 2010, service businesses have a legal duty not to discriminate — an inaccessible site is a legal risk as well as a moral one.
// Development

Development terms

CMS#cms
A content management system for editing site content without code.
A CMS (content management system) is the admin panel a business owner uses to edit pages, publish blog posts and update images without touching HTML. Common examples: Webflow, WordPress, Sanity, Contentful, Payload.
Static site#static-site
A site served as pre-built HTML with no runtime backend.
A static site is generated at build time and served as flat HTML from a CDN. It's fast, cheap, and hard to hack — a good fit for most marketing sites. Static doesn't mean unchanging: content updates trigger a rebuild.
Server-side rendering (SSR)#ssr
Rendering a page's HTML on the server before sending it.
SSR generates the full HTML on the server on every request. That means Google and social crawlers see real content instantly, and the page feels fast on first paint — critical for SEO on any site with dynamic data.
Single-page application (SPA)#spa
A JS app that renders the whole site client-side.
A SPA runs entirely in the browser after one initial load. Great for logged-in dashboards, poor for marketing pages that need to rank — search engines see an empty shell unless SSR or prerendering is added on top.
Headless CMS#headless-cms
A CMS that stores content and exposes it via API — no built-in frontend.
A headless CMS separates content storage from the site rendering it. You get an admin UI for editors and an API for developers, so the same content can feed a website, an app and a marketing email without duplication.
API#api
A programmatic interface for one system to talk to another.
An API (application programming interface) lets one piece of software request data or actions from another. On a website, APIs power things like booking calendars, Stripe payments, or a CMS feeding the page.
Frontend#frontend
The part of a site that runs in the browser.
The frontend is everything a visitor sees and interacts with — HTML, CSS, JavaScript. It's the layer that turns design mockups into a real, clickable site.
Backend#backend
The server-side systems that power the site.
The backend is the database, business logic and APIs behind a site. On a brochure site it's minimal; on a booking platform or portal it's most of the work.
// SEO

SEO terms

SEO#seo
Search engine optimisation — making a site findable in Google.
SEO is the ongoing practice of aligning a site with what search engines rank: relevant content, technical health, credible backlinks and clean user signals. It's the difference between a site that exists and a site that gets found.
On-page SEO#on-page-seo
Optimisation of a page's own content and HTML.
On-page SEO covers what lives on the page: title tag, meta description, headings, keyword usage, internal links, image alt text and schema. It's the half of SEO you fully control.
Off-page SEO#off-page-seo
External signals that influence a site's ranking.
Off-page SEO is everything that happens away from your site: backlinks, brand mentions, directory listings, Google Business Profile reviews. It's how Google decides whether other people vouch for you.
Technical SEO#technical-seo
The infrastructure layer of SEO — speed, crawlability, indexing.
Technical SEO covers whether Google can find, crawl and understand a site: sitemap, robots.txt, structured data, canonical tags, page speed, mobile usability. Get it wrong and no amount of content will save you.
Local SEO#local-seo
SEO tuned to specific geographic queries.
Local SEO is what makes 'plumber near me' or 'web design Fife' rank the right business. It's built on Google Business Profile, consistent NAP citations, service-plus-town pages, local schema and reviews.
Schema markup#schema-markup
Structured data that tells search engines what a page is about.
Schema markup is JSON-LD (or microdata) that labels page content — this is a business, this is a review, this is an FAQ. It unlocks rich snippets in Google search results and is one of the highest ROI SEO changes most sites are missing.
Meta description#meta-description
The short summary shown under a page's title in Google.
The meta description doesn't directly affect rankings but heavily affects click-through rate. Aim for under 160 characters, include the primary keyword, and write it like ad copy — because that's what it is.
Title tag#title-tag
The clickable headline of a page in search results.
The title tag is the most important on-page SEO element on any given page. Keep it under 60 characters, front-load the keyword, and make sure each page has a unique one — no site should have five pages titled 'Home'.
Canonical URL#canonical-url
The authoritative version of a page when duplicates exist.
A canonical URL tells search engines which version of a page to index when the same content is reachable via multiple URLs (with/without trailing slash, tracking parameters, etc). Without it, ranking power gets split.
Keyword research#keyword-research
Finding the search terms real customers actually type.
Keyword research is the process of discovering what your audience searches for, in their own words. It's the difference between writing a page about 'bespoke lighting solutions' and a page about 'kitchen ceiling light installation Edinburgh'.
SERP#serp
Search engine results page.
The SERP is the page Google returns after a query. Modern SERPs are crowded with ads, Map Packs, People Also Ask blocks and AI overviews — organic ranking is worth less than it was, and structured data is how you claw back visibility.
E-E-A-T#eeat
Experience, Expertise, Authoritativeness, Trust — Google's quality signals.
E-E-A-T is Google's framework for judging content quality. In practice it means named authors with real credentials, first-hand experience, transparent contact info, and demonstrable trust signals. It's why author bios and case-study proof matter to ranking in 2026.
// Performance

Performance terms

Core Web Vitals#core-web-vitals
Google's three headline page-speed metrics.
Core Web Vitals are three field metrics Google uses as ranking signals: Largest Contentful Paint (loading), Interaction to Next Paint (responsiveness) and Cumulative Layout Shift (visual stability). Fail them and you're competing with one hand tied behind your back.
LCP#lcp
Largest Contentful Paint — how fast the main content shows up.
LCP measures how long it takes the biggest visible element (usually the hero image or headline) to render. Google's threshold is 2.5s. Above 4s is a fail — and correlates strongly with drop-off.
CLS#cls
Cumulative Layout Shift — how much a page jumps as it loads.
CLS measures unexpected layout shifts — the thing that makes you tap the wrong button because an ad loaded late. Google's target is under 0.1. The main causes are images without dimensions and web fonts swapping.
CDN#cdn
Content Delivery Network — servers that cache your site globally.
A CDN caches your site on servers around the world so a visitor in Aberdeen isn't waiting for a response from a datacentre in Virginia. Modern hosts (Vercel, Netlify, Cloudflare) include one by default.
Lazy loading#lazy-loading
Deferring loading of below-the-fold images and iframes.
Lazy loading skips downloading images and iframes until the visitor scrolls near them. It's a one-line HTML attribute (loading="lazy") and one of the highest-return performance wins any site can make.
// Content

Content terms

Call to action (CTA)#call-to-action
The instruction that tells a visitor what to do next.
A CTA is the button or link that names the next step: 'Book a call', 'Get a quote', 'Start your project'. Generic 'Learn more' CTAs convert badly; specific outcome-led CTAs win.
Value proposition#value-proposition
A one-line statement of who a business is for and what it does for them.
A value proposition names the customer, the outcome and the reason to choose you. Most homepages skip it in favour of a company tagline — which reads well internally and converts nothing.
Landing page#landing-page
A focused page built to convert traffic from one specific source.
A landing page is designed around a single message, audience and CTA — usually to receive traffic from an ad, campaign, or search intent. It's not just any page you land on; it's a purpose-built one.
Microcopy#microcopy
The small bits of text on buttons, forms and error messages.
Microcopy is the writing most designers forget: button labels, form field hints, empty states, error messages. Done well it removes friction; done badly it silently kills conversions.
// Analytics

Analytics terms

Conversion rate#conversion-rate
The percentage of visitors who take the desired action.
Conversion rate is enquiries (or purchases) divided by visitors. For UK service businesses, 2-5% is typical for a decent site; 6%+ is a genuinely good one. Sub-1% usually means the headline, offer or trust signals are broken — not the design.
Bounce rate#bounce-rate
The percentage of visitors who leave without a second interaction.
Bounce rate is a soft signal — high on a blog post that answers the question is fine; high on a homepage means the headline isn't landing. Modern analytics (GA4) has replaced it with 'engagement rate', which is the same idea flipped.
UTM parameters#utm-parameters
URL tags that let you track where traffic came from.
UTM parameters are extra bits appended to a URL (utm_source, utm_medium, utm_campaign) so analytics can attribute a visit to a specific email, ad or post. Without them, most 'direct' traffic is actually mystery traffic.
// Hosting

Hosting terms

SSL / HTTPS#ssl-https
The encryption layer that makes a site show a padlock.
SSL (now technically TLS) encrypts traffic between browser and server. HTTPS is the URL that results. Google has treated it as a ranking factor since 2014 and browsers now show sites without it as 'Not Secure'.
DNS#dns
The address book that maps domains to servers.
DNS (Domain Name System) translates a domain like project-pixel.com into the IP address of the server hosting it. Most launch-day drama is DNS drama — records propagating, TTLs not respected, MX records missed.
Domain name#domain-name
The human-readable web address of a site.
A domain is what people type in the browser bar. Short, memorable and brandable beats keyword-stuffed every time — 'projectpixel.com' outlives 'best-cheap-web-design-scotland.co.uk'.
Uptime#uptime
The percentage of time a site is available.
Uptime is the reliability metric hosts advertise. 99.9% sounds fine — it's still ~8.7 hours of downtime a year. For a business that runs enquiries through its site, target 99.99%+ and a host that publishes a real status page.

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