Internet glossary: 500 terms explained in plain language

The internet industry loves acronyms and jargon. This glossary explains nearly 500 terms in plain language — from hosting and domains to SEO, security, and web development. Bookmark this page: we update it regularly. And if you are looking for reliable SEO hosting, check out our plans.

A

• A/B testing — comparing two versions of a page to see which performs better (e.g. more sales).
• A record — DNS record that points a domain name to a server's IPv4 address.
• AAAA record — same as an A record, but for IPv6 addresses.
• Above the fold — the part of a page visible without scrolling; prime real estate for your message and CTA.
• Access log — server journal of every visit: who requested what, and when.
• Adaptive design — design with several fixed layouts for different screen sizes.
• Addon domain — an extra domain on the same hosting account, running a separate site.
• Admin panel — the protected area of a site used to manage content and settings.
• Adware — software that forcibly displays ads, often installed without the user's knowledge.
• Affiliate marketing — earning commissions by recommending other companies' products.
• AJAX — technique that lets a page load new data without a full reload.
• Algorithm — the set of rules by which, for example, Google ranks search results.
• Alt text — text description of an image; important for accessibility and image SEO.
• AMP — Google's accelerated mobile pages format; largely abandoned today.
• Anchor text — the visible text of a link; tells Google what the target page is about.
• Anycast — network technique where many servers share one IP, so visitors connect to the nearest one.
• Apache — the oldest and long the most widespread web server software.
• API — interface through which programs exchange data (e.g. your site and a payment provider).
• API key — secret code an application uses to identify itself to an API.
• Auth code (EPP) — the domain password required to transfer it to another registrar.
• Authentication — verifying a user's identity (password, 2FA, biometrics).
• Authorization — checking what a logged-in user is allowed to do.
• Autoresponder — automatic email reply (e.g. "out of office until Monday").
• Auto-scaling — automatically adding server resources when traffic grows.
• AVIF — modern image format with better compression than JPEG and WebP.

B

• Backend — the part of a site that runs on the server: database, logic, data processing.
• Backlink — a link from someone else's site to yours; one of the strongest SEO signals.
• Backorder (domain) — reserving a taken domain so you grab it the moment it expires.
• Backup — a spare copy of your site and database; daily backups mean you never lose more than one day of data.
• Bandwidth — the amount of data your site transfers to visitors per month.
• Bare metal server — a physical server without virtualization, dedicated to one customer.
• Beta version — a software release meant for testing before the official launch.
• Black hat SEO — forbidden SEO techniques that earn a penalty once Google catches them.
• Blacklist — a list of blocked IP addresses, domains, or mail servers.
• Blog — the article section of a site; brings businesses search traffic.
• Bot — a program that performs automated tasks online (good: Googlebot; bad: spam bots).
• Botnet — a network of infected computers attackers use, e.g. for DDoS attacks.
• Bounce (email) — a returned message that could not be delivered.
• Bounce rate — the share of visitors who leave after viewing just one page.
• Breadcrumbs — "Home → Blog → Article" navigation showing visitors where they are.
• Breakpoint — the screen width at which a responsive design changes its layout.
• Browser — the program used to view websites: Chrome, Safari, Firefox, Edge.
• Brute force attack — guessing a password by trying thousands of combinations per second.
• Buffer — temporary memory for data being processed (e.g. video streaming).
• Bug — a software error causing unwanted behavior.
• Byte — the basic unit of data; 1 GB is roughly a billion bytes.
• Database — organized storage for a site's data (content, users, orders).

C

• Cache — a saved, ready-made version of a page or data so it isn't generated from scratch each time; key to speed.
• Canonical URL — a tag telling Google which is the "main" version of a page when several similar ones exist.
• CAPTCHA — the "are you a robot" test protecting forms from spam.
• Catch-all email — an address that receives all mail sent to non-existent addresses on your domain.
• ccTLD — country-code domain extension: .rs, .de, .at, .ch.
• CDN — a worldwide network of servers delivering content from the location nearest to each visitor; dramatically speeds up a site.
• CGI — an older standard for running scripts on a web server.
• Chatbot — an automated assistant on a site answering common questions.
• Checkout — the payment process in an online store; every extra step costs sales.
• chmod — Linux command for setting file permissions (e.g. 644 for files, 755 for folders).
• CLS — Core Web Vitals metric measuring how much elements "jump" while a page loads.
• Cloud hosting — hosting on a network of connected servers instead of one machine; easier scaling.
• CMS — content management system for running a site without coding; WordPress is the best known.
• Colocation — housing your own physical server in someone else's data center.
• Container — an isolated environment packaging an app with everything it needs (e.g. Docker).
• Cookie — a small file a site stores in your browser to recognize you on the next visit.
• cPanel — the most widespread hosting control panel.
• CPC — cost per click in advertising.
• CPM — cost per thousand ad impressions.
• CPU — the server's processor; core count determines how many requests it can handle at once.
• Crawl budget — how many pages Google crawls on your site in a given period.
• CRM — software for managing customer relationships and contacts.
• Cron job — a scheduled server task that runs automatically (e.g. backup at 3 a.m.).
• CSS — the language defining a site's appearance: colors, fonts, layout.
• CSV — comma-separated tabular data format; universal for import/export.
• CTA — call to action: the button or link leading to your goal ("Order", "Book now").
• CTR — the percentage of people who click your result or ad relative to how often it's shown.
• cURL — command-line tool for sending HTTP requests; handy for testing.
• CVE — the public database of known software security vulnerabilities.

D

• Dark mode — a dark interface theme; more and more sites offer it.
• Dashboard — an overview panel with your key data and shortcuts.
• Data center — a facility with thousands of servers, redundant power and cooling.
• DDoS — an attack that takes a site down by flooding it with fake traffic; good protection absorbs it.
• Dedicated server — an entire physical server rented just for you; maximum power and control.
• Deployment — publishing a new version of a site or application to the server.
• Dev environment — a local or separate copy of the site where developers make changes.
• Disk space — server storage for your files, images, database, and email.
• DKIM — a digital signature proving an email really comes from your domain.
• DMARC — a policy telling mail servers what to do with messages that fail SPF/DKIM checks.
• DNS — the "phone book of the internet" connecting a domain name to the server hosting the site.
• DNS propagation — the time (up to 24–48h) for a DNS change to spread worldwide.
• DNSSEC — cryptographic protection of DNS records against forgery.
• Docker — the most popular platform for packaging applications into containers.
• Domain — your site's address (e.g. seohosting.rs); registered on a yearly basis.
• Domain Authority — Moz's 1–100 score of a domain's strength based on links.
• Doorway page — a page built only for search engines, worthless to people; Google penalizes it.
• Downtime — the period when a site is unavailable; every minute costs trust and sales.
• Drag-and-drop builder — a tool for assembling pages by dragging elements, no code needed.
• Drupal — a powerful open-source CMS for more complex projects.
• Duplicate content — the same content on multiple URLs; confuses Google and dilutes rankings.
• Dwell time — how long a visitor stays on your page before returning to search results.
• Dynamic DNS — automatic DNS updates when an IP address changes.

E

• E-commerce — selling products and services over the internet.
• E-E-A-T — Google's content quality criteria: experience, expertise, authoritativeness, trust.
• Edge server — a CDN server near the visitor that delivers cached content.
• Elementor — the most popular drag-and-drop builder for WordPress.
• Email hosting — email accounts on your own domain (name@yourcompany.com); more professional than free addresses.
• Email spoofing — forging an email's sender; SPF, DKIM, and DMARC prevent it.
• Encryption — scrambling data so only someone with the key can read it.
• EPP code — see Auth code; the password for a domain transfer.
• Error log — the server's error journal; the first place to look when a site breaks.
• EXIF — metadata in photos (camera, location, date); often worth removing for privacy.
• Exit rate — the share of visits that end on a particular page.
• External link — a link from your site to someone else's.

F

• Failover — automatic switch to a backup server when the primary one fails.
• FAQ schema — structured data showing questions and answers directly in Google results.
• Favicon — the small site icon in browser tabs and bookmarks.
• FCP — time until the first content appears on screen; an early measure of loading speed.
• Featured snippet — the highlighted answer at the top of Google results, "position zero".
• Fiber optics — optical internet; the backbone of fast links between data centers.
• File manager — control panel tool for working with files without FTP.
• Firewall — a protective wall filtering network traffic and blocking attacks.
• Footer — the bottom section of a site with contacts, links, and legal info.
• Form spam — automated spam through contact forms; CAPTCHA and honeypot fields solve it.
• Framework — a ready-made foundation for building applications (Laravel, Django, Next.js).
• Frontend — the part of a site visitors see and interact with in the browser.
• FTP — an older protocol for transferring files to a server; SFTP is recommended today.
• FTPS — FTP with SSL/TLS encryption.
• Full backup — a complete copy of everything: files, database, email, settings.
• Funnel — the visitor's path from first contact to purchase, step by step.

G

• Gateway — a crossing point between two networks or systems (e.g. payment gateway).
• GDPR — the European data protection regulation; mandatory for sites with EU visitors.
• Geotargeting — adapting content or ads to the visitor's location.
• Git — the version control system for code; the industry standard.
• GitHub — the largest platform for hosting Git projects and developer collaboration.
• Google Analytics — Google's free website traffic analysis tool.
• Google Business Profile — a free company profile on Google Maps and Search; the foundation of local SEO.
• Google Search Console — Google's free tool showing how your site performs in search.
• Googlebot — Google's robot that crawls and indexes websites.
• GraphQL — a modern API query language where the client chooses exactly which data it wants.
• Gravatar — a global avatar tied to an email address, common in comment sections.
• Green hosting — hosting powered by renewable energy.
• Grey hat SEO — techniques in the grey zone between allowed and punishable.
• gTLD — generic domain extensions: .com, .net, .org, .shop.
• Guest post — an article published on someone else's blog, usually for a backlink.
• Gzip — compression that shrinks files by up to 70% before sending them to the browser.

H

• Hardening — a set of measures making a server or CMS more resistant to attacks.
• Hash — a one-way "fingerprint" of data; how passwords are stored safely.
• Heading tags (H1–H6) — the heading hierarchy on a page; H1 is the main one and there should be only one.
• Heatmap — a visual map of where visitors click and how far they scroll.
• Hex color code — color notation like #1a73e8 used by CSS and design tools.
• Header — the top section of a site with logo and navigation; or an HTTP request header.
• Homepage — the front page of a website.
• Honeypot — a hidden field or decoy system that catches bots and attackers.
• Hosting — the service of keeping your site on a server that is always online, available 24/7.
• Hotlinking — others embedding your images directly, spending your bandwidth.
• Hreflang — a tag telling Google which language and market each page version targets.
• .htaccess — Apache configuration file for redirects, caching, and protection.
• HTML — the language every web page's structure is written in.
• HTTP — the protocol browsers and servers use to exchange data.
• HTTPS — encrypted HTTP; the padlock in the browser, mandatory for any serious site.
• HTTP/2 — a faster protocol version loading multiple files over one connection.
• HTTP/3 — the newest version, built on QUIC; faster on unreliable networks.
• HTTP status code — the server's three-digit reply: 200 OK, 301 redirected, 404 not found, 500 error.
• Hyperlink — a clickable connection to another page or resource; the foundation of the web.
• Hypervisor — software dividing a physical server into several virtual ones (the basis of VPS).

I

• ICANN — the organization globally managing the domain name system.
• Iframe — embedding another page inside yours (e.g. a YouTube video or map).
• IMAP — email protocol syncing mail across all devices; messages stay on the server.
• Impression — one display of your search result or ad to a user.
• Inbound marketing — attracting customers with useful content instead of aggressive ads.
• Incident — an unplanned outage or service degradation.
• Indexing — the process by which Google adds your pages to its search database.
• Inode — one file or folder on the server; hosting plans often have inode limits.
• INP — Core Web Vitals metric measuring how fast a page reacts to clicks.
• Internal link — a link between two pages of the same site; helps both visitors and SEO.
• IOPS — disk input/output operations per second; NVMe has many times the IOPS of SSD.
• IP address — a device's numeric address on the network (e.g. 185.119.90.10).
• IPv4 — the classic IP address format; addresses are practically exhausted.
• IPv6 — the new format with a practically unlimited number of addresses.
• ISP — internet service provider; the company connecting you to the internet.

J

• JavaScript — the programming language that makes pages interactive; runs in every browser.
• Joomla — an open-source CMS, once WordPress's main rival.
• JPEG — the most widespread photo format on the web.
• jQuery — a once-indispensable JavaScript library; often unnecessary today.
• JSON — a lightweight format for exchanging data between applications.
• JSON-LD — the recommended format for adding schema markup to a page.
• JWT — a compact token for securely passing identity between systems.

K

• Kernel — the operating system core managing the hardware.
• Keyword — the phrase people type into search that you target with content.
• Keyword stuffing — cramming text with keywords; Google penalizes it.
• Compression — reducing file sizes for faster transfer (Gzip, Brotli).
• Control panel — the interface for managing hosting (cPanel, Plesk).
• Conversion — the moment a visitor does what you want: buys, calls, leaves an email.
• KPI — the key performance indicator you track (visits, inquiries, sales).
• KVM — virtualization technology with fully isolated resources; common in VPS.

L

• Landing page — a page with one goal and one CTA, usually an ad destination.
• Laravel — the most popular PHP framework for web applications.
• Latency — signal delay between user and server; lower latency = faster site.
• Lazy loading — loading images only when the visitor scrolls to them; saves time and bandwidth.
• LCP — Core Web Vitals metric: time until the largest element appears; aim for under 2.5 s.
• Let's Encrypt — free SSL certificates your host renews automatically.
• Lightbox — an enlarged image view over a dimmed page.
• Link building — systematically earning quality backlinks.
• Linux — the operating system running the vast majority of web servers.
• LiteSpeed — a fast web server, often twice as fast as Apache for WordPress.
• Load balancer — distributes traffic across servers so none gets overloaded.
• Localhost — your own computer as a server (address 127.0.0.1); for local development.
• Log file — the server's event journal; gold when troubleshooting.
• Login — signing a user into the protected part of a site.
• Local SEO — optimizing so customers in your city find you ("plumber Vienna").
• Long-tail keywords — longer, specific phrases with fewer searches but higher conversion rates.

M

• Mailing list — your base of email subscribers who receive the newsletter.
• Maintenance mode — a temporary "site under maintenance" page during work.
• Malware — malicious code injected into a site; regular scanning catches it before damage is done.
• Managed hosting — hosting where the provider handles updates, security, and optimization.
• MariaDB — a fast, open replacement for MySQL; fully WordPress-compatible.
• MD5 — an outdated hash algorithm; unsafe for passwords today.
• Memcached — in-memory caching system that offloads the database.
• Meta description — the page description in search results; up to 160 characters that sell the click.
• Meta title — the page title in the browser tab and Google results; the most important on-page SEO element.
• Metric — any measurable value you track (visits, conversions, speed).
• Migration — moving a site from one host to another; with a good plan, zero downtime.
• Minification — stripping spaces and comments from code for smaller files.
• Mixed content — HTTP resources on an HTTPS page; breaks the padlock and trust.
• Mobile optimization — making a site work well on phones; Google indexes the mobile version.
• Monitoring — automated 24/7 tracking of site availability and performance.
• Multisite — one WordPress installation running multiple sites.
• MX record — DNS record determining which server receives email for your domain.
• MySQL — the most widespread database on the web; powers WordPress too.

N

• Name server — the server holding a domain's DNS records; changed when switching hosts.
• NAT — technique letting multiple devices share one public IP address.
• Navigation — the site menu; clear navigation keeps visitors around.
• Newsletter — a periodic email to subscribers; one of the most profitable channels.
• Nginx — a modern web server known for speed under heavy load.
• Niche — the narrow market or topic a site focuses on.
• Node.js — a JavaScript runtime for server-side applications.
• Nofollow — a link attribute telling Google not to pass SEO value.
• Noindex — a tag forbidding Google from listing a page in results.
• npm — the package manager for JavaScript projects.
• NS record — DNS record showing which name servers run the domain.
• NVMe — the fastest generation of drives, up to 10x faster than classic SSDs.

O

• OAuth — the standard for logging in via a third-party service ("Sign in with Google").
• Off-page SEO — everything outside your site that affects rankings, above all backlinks.
• On-page SEO — optimization on the site itself: titles, content, speed, structure.
• Onboarding — guiding a new user into a product or service.
• Open Graph — meta tags controlling how a link looks on social networks.
• Open source — software with public code, free to use and modify.
• Operating system — the server's base software; Linux dominates the web.
• Organic traffic — visits from unpaid search results; the goal of SEO.
• Origin server — the source server a CDN pulls content from.
• OTP — a one-time password, usually as a second login factor.
• Outbound link — see External link.
• Overselling — selling more resources than a server has, betting nobody uses them all.

P

• Page speed — how fast a page loads; directly affects rankings and sales.
• PageRank — Google's historic link-based page scoring algorithm.
• Pagination — splitting long lists into pages (1, 2, 3...).
• Parked domain — a registered domain with no site, often showing ads.
• Payment gateway — the service processing card payments on a site.
• Penetration test — a controlled "attack" on a system to uncover weaknesses.
• Permalink — the permanent URL of a page or article.
• PHP — the language powering WordPress and most of the web; a newer version means a faster site.
• phpMyAdmin — web tool for managing MySQL databases from the control panel.
• Phishing — scams using fake sites and messages to steal passwords and cards.
• Ping — a test of server availability and response time.
• Plugin — an add-on extending a CMS; too many plugins slow a site down.
• PNG — lossless image format, ideal for logos and graphics with transparency.
• POP3 — an older email protocol downloading mail to a single device.
• Pop-up — a window appearing over the page; useful in moderation, annoying in excess.
• Port — a server's numeric "door": 80 for HTTP, 443 for HTTPS, 22 for SSH.
• PostgreSQL — an advanced open-source database.
• PPC — pay-per-click advertising (Google Ads, Meta Ads).
• Proxy — an intermediary between user and server; a reverse proxy protects and speeds up a site.
• PTR record — the reverse DNS record, important for mail server reputation.
• Push notifications — messages a site sends users even when they're not on it.
• PWA — a web app behaving like a mobile app: works offline, has an icon.
• Python — a versatile programming language, popular for automation and AI.

Q

• QR code — the square code a phone scans to open a link.
• Query — what a user types into search, or a request sent to a database.
• Query string — URL parameters after the ? sign (e.g. ?utm_source=newsletter).
• Quality Score — Google's ad quality rating that affects your cost per click.

R

• RAID — combining multiple drives for speed and failure protection.
• RAM — the server's working memory; more RAM means more simultaneous visitors without slowdown.
• Ranking — your site's position in search results for a given keyword.
• Ransomware — malware that encrypts data and demands ransom; the defense is a good backup.
• Redirect 301 — permanent redirect that passes SEO value to the new URL.
• Redirect 302 — temporary redirect, without passing SEO value.
• Redis — an ultra-fast in-memory store for caching and sessions.
• Registry — the organization running one extension (e.g. RNIDS for .rs).
• Registrant — the domain owner; always register a domain in your own name, not the agency's.
• Registrar — the company through which you register a domain.
• Rel attribute — extra link properties: nofollow, sponsored, ugc.
• Remarketing — showing ads to people who already visited your site.
• Reseller hosting — a hosting plan you resell to your own clients.
• Responsive design — a site automatically adapting to every screen size.
• REST API — the most widespread web API style, based on HTTP methods.
• Reverse proxy — a server in front of your site that receives requests, caches, and protects (e.g. Nginx, CDN).
• Rich snippets — enriched search results: stars, prices, images.
• Robots.txt — the file telling search engine robots what they may crawl.
• Rollback — restoring the previous version of a site when a change goes wrong.
• Root access — full administrative control over a server.
• RSS — a format for automatically following new posts from websites.

S

• SaaS — software as a service: you pay a subscription, install nothing (e.g. Shopify).
• Sandbox — an isolated environment for safe testing.
• Schema markup — structured data explaining your content to Google (product, recipe, FAQ).
• Screen reader — software reading pages aloud for visually impaired users; that's why alt text matters.
• Search engine — Google, Bing, DuckDuckGo.
• SEO — optimizing a site for better positions in search results.
• SERP — the search results page the user sees.
• Server — a computer storing websites and serving them to visitors 24/7.
• Server-side rendering — generating the page on the server before sending it to the browser; good for SEO.
• Session — one visit to a site, with all its actions.
• SFTP — secure file transfer over SSH; the standard instead of FTP.
• SHA-256 — a modern hash algorithm, standard for digital signatures.
• Shared hosting — multiple sites sharing one server; the most affordable entry into hosting.
• Sitemap (XML) — the list of all your pages helping Google find them.
• Slug — the part of a URL describing the page (e.g. /wordpress-hosting).
• SMTP — the protocol for sending email.
• Snapshot — a point-in-time image of the whole server, restorable in one click.
• SPA — a single-page application that loads once and changes content without refreshing.
• Spam — unwanted bulk messages; in SEO, also manipulative content.
• SPF — DNS record listing who may send email from your domain.
• Spyware — software secretly tracking users and stealing data.
• SQL — the language for working with databases.
• SQL injection — an attack injecting SQL code through forms; a WAF blocks it.
• SSD — a drive with no moving parts, many times faster than classic hard disks.
• SSH — encrypted command-line access to a server.
• SSL certificate — technology encrypting the connection between visitor and site (https); mandatory for security and Google.
• Staging — a copy of your site for safely testing changes before publishing.
• Status code 404 — "page not found"; too many 404s hurt user experience.
• Status code 500 — a general server error; step one is checking the error log.
• Status code 503 — service temporarily unavailable, e.g. during maintenance.
• Sticky header — a menu that stays visible while scrolling.
• Subdomain — a domain under your main one (blog.yourcompany.com); free with most hosts.
• SVG — vector format for icons and logos; sharp at any size.

T

• Tag — a label for grouping content, or an HTML element.
• Template — a ready-made design you fill with your content.
• Terminal — the text interface for controlling a server with commands.
• Thumbnail — a reduced preview of an image or video.
• Throttling — deliberate slowing of resources once a limit is exceeded.
• Data center tier — the I–IV reliability classification of data centers.
• TLD — the domain extension: .com, .rs, .org.
• TLS — the modern encryption protocol; what "SSL" actually refers to today.
• Tracking pixel — an invisible 1x1 image measuring opens and visits.
• Traffic — the total visits to a site.
• Domain transfer — moving a domain to another registrar using the EPP code.
• Trojan — malware disguised as a useful program.
• TTFB — time to first byte of the server's response; the basic measure of hosting speed.
• TTL — how long a DNS record is cached before being rechecked.
• 2FA — two-factor login: password plus a code from your phone; mandatory for admin accounts.
• Typosquatting — registering misspelled versions of someone's brand domain for fraud.

U

• Ubuntu — the most popular Linux distribution on servers.
• UDP — a fast network protocol without delivery confirmation; used by HTTP/3.
• UI — user interface: everything the user sees and touches.
• Unicode — the standard enabling all the world's scripts on the web, including Cyrillic.
• Unmetered bandwidth — unmeasured traffic; watch for "fair use" in the fine print.
• Update — refreshing software; regular updates are a site's first line of defense.
• Uptime — the percentage of time a site is available; 99.9% means up to 9 hours of outages a year.
• URL — a page's full address (https://seohosting.rs/en/wordpress-hosting).
• Usability — how easy a site is to use.
• User agent — the browser or bot identification the server sees.
• UTM parameters — URL add-ons tracking where a visit came from.
• UX — user experience: how using the site feels.

V

• Varnish — a powerful HTTP cache accelerating high-traffic sites.
• Domain verification — proving you own a domain (e.g. for Search Console).
• Video hosting — putting videos on specialized services (YouTube, Vimeo) instead of your own server.
• Viewport — the visible area of a page on a device's screen.
• Virtualization — dividing a physical server into several independent virtual ones.
• Virus — malware that spreads by infecting files.
• VPN — an encrypted tunnel hiding your location and protecting you on public networks.
• VPS — virtual private server: guaranteed resources and more control than shared hosting.
• Vulnerability — a software weakness an attacker can exploit.

W

• W3C — the organization defining web standards.
• WAF — a web application firewall blocking attacks before they reach your site.
• Web application — a site with program-like functionality: banking, CRM, webmail.
• Web design — shaping a site's look and experience.
• Web server — software serving pages to visitors: Apache, Nginx, LiteSpeed.
• Webhook — an automatic message one system sends another when something happens (e.g. a new order).
• Webmail — reading email in the browser, without a mail client.
• WebP — Google's image format, 25–35% smaller than JPEG at the same quality.
• WebSocket — a permanent two-way connection between browser and server, for chat and live data.
• Website builder — a no-code site building tool (Wix, Squarespace).
• White hat SEO — optimization within Google's rules; the only sustainable kind.
• WHOIS — the public database of domain owners.
• Widget — a small functional block on a page (weather, latest posts).
• Wildcard SSL — a certificate covering all subdomains too (*.yourcompany.com).
• Wireframe — a layout sketch of a page before design.
• WooCommerce — the most popular online store plugin for WordPress; for speed, get proper WordPress hosting.
• WordPress — the world's most popular CMS, powering over 40% of the internet.
• WordPress theme — the design package determining a WordPress site's look.
• WP-CLI — the command line for managing WordPress without the admin panel.
• WWW — the historic domain prefix; a matter of choice today, with a mandatory redirect to one version.

X

• XML — a format for structured data; sitemaps use it.
• XML sitemap — see Sitemap; the site map for search engines.
• XSS — an attack injecting malicious JavaScript into a page.

Y

• YAML — a human-readable format for configuration files.
• Yoast SEO — the best-known SEO plugin for WordPress.

Z

• Zero-day — a vulnerability with no patch yet; the most dangerous kind.
• ZIP — an archive packing multiple files into one, with compression.
• Zone file (DNS) — the file containing all of a domain's DNS records.

Extra terms: A–D

• Accessibility — how usable a site is for people with disabilities; the standard is WCAG.
• Ad blocker — a browser extension blocking ads; used by over 30% of users.
• Bootstrap — the best-known CSS framework for quickly building responsive sites.
• Brotli — Google's compression, more efficient than Gzip.
• Browser cache — the cache in the visitor's browser; repeat visits load instantly.
• CAA record — DNS record defining who may issue SSL certificates for your domain.
• Child theme — WordPress sub-theme preserving your changes when the parent theme updates.
• Cloudflare — the world's best-known CDN and protection service.
• CNAME record — DNS record pointing one name to another (e.g. www to the main domain).
• Composer — the package manager for PHP projects.
• Content marketing — attracting customers with useful content: blog, guides, video.
• Conversion rate — the share of visitors completing the desired action; e-commerce averages 2–3%.
• Core update — a major change to Google's algorithm that can significantly shift rankings.
• CSRF — an attack tricking a logged-in user into an unwanted action; tokens prevent it.
• Dark web — the part of the internet reachable only via special networks like Tor.
• Deep link — a link leading straight to a specific page, not the homepage.
• DNS lookup — checking a domain's DNS records; each lookup adds milliseconds to load time.
• Domain lock — locking a domain against unauthorized transfer.
• Domain privacy (WHOIS protection) — hiding the owner's personal data from the public WHOIS database.
• DoS — a denial-of-service attack from a single source; DDoS is the same attack from thousands of machines.
• Dropshipping — a store without its own warehouse; the supplier ships directly to the customer.

Extra terms: E–K

• Edge computing — processing data on servers near the user instead of a central data center.
• Email alias — an extra name for an existing mailbox (info@ and contact@ in one inbox).
• Email forwarding — automatically passing mail on to another address.
• Email marketing — direct communication with subscribers; ROI up to $36 per dollar spent.
• Evergreen content — content that stays relevant for years and keeps bringing visits.
• Fair use policy — the "reasonable use" rules behind unlimited resources.
• First-party cookies — your own site's cookies; third-party cookies are being phased out.
• Freemium — a model where the basic service is free and advanced features are paid.
• Google Ads — Google's paid advertising platform for search and its display network.
• Google Fonts — a free web font library; best hosted locally due to GDPR.
• Google penalty (manual action) — a manual punishment for rule violations; visible in Search Console.
• GTmetrix — a popular site speed tool with detailed recommendations.
• Hamburger menu — the three-line icon opening mobile navigation.
• HSTS — a header instructing the browser to always open the site via HTTPS.
• HTML5 — the current HTML version: video, audio, and semantic elements without plugins.
• IDN — internationalized domains with non-Latin characters (e.g. Cyrillic .срб).
• Incognito mode — a browser mode that saves no history or cookies.
• Influencer marketing — promotion via people with large social audiences.
• Interstitial — a full-screen ad; Google penalizes intrusive ones on mobile.
• IP blocking — denying access to specific IP addresses.
• Keylogger — malware recording every keystroke, including passwords.
• Keyword cannibalization — several of your pages targeting the same keyword and sabotaging each other.
• Keyword difficulty — a score of how hard it is to rank for a keyword.
• Kubernetes — a system for orchestrating large numbers of containers.

Extra terms: L–R

• Lighthouse — Google's built-in tool scoring performance, accessibility, and SEO.
• Link juice — slang for the SEO value a link passes on.
• Load testing — testing how much traffic a site can take before slowing down.
• LSCache — the LiteSpeed cache plugin for WordPress; among the fastest solutions.
• Markdown — simple text formatting syntax (# heading, **bold**).
• Meta keywords — an obsolete meta tag Google has ignored since 2009.
• Mobile-first index — Google ranks based on your mobile version, not desktop.
• ModSecurity — an open-source WAF module for Apache and Nginx.
• MTA — the software transferring email between servers (Postfix, Exim).
• Next.js — a React framework with server-side rendering; excellent for SEO.
• Noopener/noreferrer — attributes protecting your site on links opening in new tabs.
• NPS — a -100 to 100 score of how likely customers are to recommend you.
• Object storage — S3-style storage for large files; ideal for backups and media.
• Opt-in — the user's explicit consent (e.g. for a newsletter); mandatory under GDPR.
• Orphan page — a page with no internal links pointing to it; hard for Google to find.
• PageSpeed Insights — Google's speed tool with real user data.
• Password manager — a program generating and storing strong passwords (Bitwarden, 1Password).
• PCI DSS — the security standard mandatory for sites processing payment cards.
• Pillar page — a comprehensive central page on a topic, branching into narrower articles.
• Plesk — a hosting control panel, the main alternative to cPanel.
• Preload — an instruction telling the browser to load key resources with priority.
• Progressive enhancement — an approach where the site works everywhere, and modern browsers get more.
• Punycode — the ASCII notation of internationalized domains (xn--...).
• QUIC — Google's transport protocol that HTTP/3 runs on.
• Rate limiting — capping requests per user; defends against overload and attacks.
• React — the most popular JavaScript library for building interfaces.
• Redirect chain — a chain of redirects (A→B→C); slows the site and wastes crawl budget.
• Referral traffic — visits arriving via links from other websites.
• Regex — regular expressions: powerful pattern-based text search and processing.
• Robots meta tag — a page-level tag: index/noindex, follow/nofollow.

Extra terms: S–Z

• Salt — a random addition to passwords before hashing; defeats bulk cracking.
• Serverless — a model where code runs without you managing a server; you pay per execution.
• Shopify — the largest SaaS platform for online stores.
• Sitelinks — the extra links under a main result in Google search.
• SMM — social media marketing.
• Soft 404 — a page that looks like an error but returns 200; confuses Google.
• Spam score — a rating of how likely your email is to land in spam.
• SSL handshake — the process of establishing the encrypted connection when a site opens.
• SSL types (DV/OV/EV) — validation levels: domain, organization, or extended.
• Tailwind CSS — the utility-first CSS framework, currently the developers' favorite.
• Time on page — the average time visitors spend on a page.
• Time to Interactive — the time until a page becomes fully usable.
• Toxic backlinks — bad links to your site that can hurt rankings.
• TXT record — DNS record for text data; carries SPF, DKIM, and verifications.
• TypeScript — JavaScript with types; reduces errors in larger projects.
• UGC — user-generated content: reviews, comments, photos.
• URL shortener — a service shortening long links (bit.ly).
• Voice search — searching by voice; favors natural, conversational phrases.
• Vue.js — an approachable JavaScript framework, popular alongside Laravel.
• Wayback Machine — the web archive preserving historical versions of websites.
• Webinar — a live online seminar; a strong B2B marketing tool.
• Whitelist — a list of explicitly allowed addresses or senders; the opposite of a blacklist.
• WP-Cron — WordPress's scheduled task system; on bigger sites replaced by a real cron.
• YouTube SEO — optimizing videos for search: title, description, tags, captions.

Missing a term? Write to us — we expand this glossary regularly. And if you need hosting that puts all these concepts into practice, see our plans.