Reference
The web acronyms cheat sheet
Every web abbreviation decoded — CMS, SSL, CDN, DNS, GA4, SEO, UX, and dozens more.
- Difficulty
- Beginner
The web loves abbreviations. This page decodes every one you're likely to encounter — sorted alphabetically so you can find any acronym in seconds.
Quick summary
This page is a quick-reference list of 80+ web acronyms. Each entry includes the full phrase and a one-line explanation. Click the links to go deeper. Use Ctrl+F / Cmd+F to find any acronym instantly.
A–C
| Acronym | Stands for | What it means |
|---|---|---|
| A/B test | A/B Testing | Showing two versions of a page to different visitors to see which performs better. |
| API | Application Programming Interface | A way for two pieces of software to talk to each other. |
| CDN | Content Delivery Network | A network of servers worldwide that serves your site's files from the location nearest to each visitor. See What is a CDN?. |
| CLS | Cumulative Layout Shift | A Core Web Vital measuring how much the page unexpectedly moves as it loads. |
| CMS | Content Management System | Software (WordPress, Webflow, etc.) that lets you edit your website without writing code. |
| CPC | Cost Per Click | The price you pay for each click in a paid ad campaign. |
| CPM | Cost Per Mille | The price you pay per 1,000 ad impressions. |
| CRM | Customer Relationship Management | Software for managing contacts, leads, and client communication. |
| CSS | Cascading Style Sheets | Code that controls the visual appearance of a web page — colors, fonts, layout. |
| CTA | Call to Action | A prompt asking visitors to do something: "Book a call," "Buy now." |
| CTR | Click-Through Rate | The percentage of people who clicked on something (a link, ad, or search result) compared to how many saw it. |
D–F
| Acronym | Stands for | What it means |
|---|---|---|
| DKIM | DomainKeys Identified Mail | An email authentication method that digitally signs outgoing emails. See DKIM records, explained. |
| DMARC | Domain-based Message Authentication, Reporting & Conformance | Email policy that controls what happens when SPF or DKIM fail. See DMARC records, explained. |
| DNS | Domain Name System | The internet's address book, translating domain names to IP addresses. See What is DNS?. |
| DDoS | Distributed Denial of Service | An attack that floods a server with traffic to knock it offline. |
| E-E-A-T | Experience, Expertise, Authoritativeness, Trustworthiness | Google's framework for evaluating content quality. |
| FCP | First Contentful Paint | A speed metric measuring when the first content appears on screen during page load. |
| FTP | File Transfer Protocol | A method for transferring files to and from a server. |
| FSE | Full Site Editing | The WordPress feature set for editing your entire site design with blocks. |
G–I
| Acronym | Stands for | What it means |
|---|---|---|
| GA4 | Google Analytics 4 | The current version of Google Analytics. See What is Google Analytics (GA4)?. |
| GTM | Google Tag Manager | A tool for managing tracking scripts without code changes. See What is Google Tag Manager?. |
| HTML | HyperText Markup Language | The code that structures web pages. |
| HTTP | HyperText Transfer Protocol | The protocol for transferring data on the web. |
| HTTPS | HyperText Transfer Protocol Secure | The encrypted version of HTTP. See SSL & HTTPS, explained. |
| IMAP | Internet Message Access Protocol | The protocol that syncs email across devices — keeps email on the server. |
| INP | Interaction to Next Paint | A Core Web Vital measuring how quickly a page responds to user input. |
J–N
| Acronym | Stands for | What it means |
|---|---|---|
| JS | JavaScript | The programming language that makes web pages interactive. |
| KPI | Key Performance Indicator | A metric that measures progress toward an important goal. |
| LCP | Largest Contentful Paint | A Core Web Vital measuring when the main visible content loads. See Core Web Vitals explained. |
| LTV | Lifetime Value | The total revenue a customer is expected to generate over time. Also CLV (Customer Lifetime Value). |
| MFA | Multi-Factor Authentication | Logging in with multiple forms of verification. See Two-factor authentication, explained. |
| MX | Mail Exchange | A DNS record type that directs email to the right mail server. |
O–R
| Acronym | Stands for | What it means |
|---|---|---|
| PCI-DSS | Payment Card Industry Data Security Standard | Security standards for businesses handling card payments. See PCI compliance, in plain English. |
| PHP | PHP: Hypertext Preprocessor | The programming language WordPress is built on. |
| POP3 | Post Office Protocol 3 | An older email protocol that downloads messages to one device. Mostly replaced by IMAP. |
| ROI | Return on Investment | The benefit gained relative to cost. |
| RSS | Really Simple Syndication | A format for distributing regularly updated content — blog posts, podcast episodes. |
S–Z
| Acronym | Stands for | What it means |
|---|---|---|
| SaaS | Software as a Service | Software delivered via a subscription over the internet — no installation needed. |
| SERP | Search Engine Results Page | The page you see after a Google search. |
| SEO | Search Engine Optimization | Improving a site to appear higher in organic search results. See What is SEO?. |
| SFTP | Secure File Transfer Protocol | Encrypted version of FTP for secure file transfers. |
| SKU | Stock Keeping Unit | A unique code for each product (or variant) in your inventory. |
| SMTP | Simple Mail Transfer Protocol | The protocol used for sending email. See What is SMTP?. |
| SPF | Sender Policy Framework | A DNS record listing authorized email-sending servers for your domain. See SPF records, explained. |
| SQL | Structured Query Language | The language used to communicate with databases. WordPress uses MySQL. |
| SSH | Secure Shell | An encrypted way to remotely access a server's command line. |
| SSL | Secure Sockets Layer | The old name for the encryption technology now called TLS. Powers HTTPS. |
| TLD | Top-Level Domain | The domain extension — .com, .org, .net, .io. |
| TLS | Transport Layer Security | The modern encryption protocol behind HTTPS (updated version of SSL). |
| TTL | Time To Live | How long a DNS record is cached before servers re-check it. |
| UI | User Interface | The visual elements users interact with on a site or app. |
| URL | Uniform Resource Locator | A complete web address — https://yoursite.com/about-us. |
| UX | User Experience | The overall experience of using a website — usability, flow, feel. |
| UTM | Urchin Tracking Module | Parameters added to URLs to track traffic sources in analytics. See UTM links for campaign tracking. |
| VPN | Virtual Private Network | Encrypts your internet connection and hides your IP address. |
| VPS | Virtual Private Server | A hosting tier offering dedicated server resources without a full dedicated machine. |
| WAF | Web Application Firewall | A firewall specifically for filtering malicious web traffic. |
| WCAG | Web Content Accessibility Guidelines | International standards for web accessibility. |
| WYSIWYG | What You See Is What You Get | An editor where the preview looks like the final output. |
| XML | Extensible Markup Language | A file format used for sitemaps and data interchange. |
Common questions
Why are there so many acronyms in web development?
The internet evolved from technical communities that loved shorthand. Many acronyms have become so standard that even everyday users encounter them. This list covers the ones you're most likely to see as a website owner.
What acronyms do I actually need to know?
For day-to-day site management, the key ones are: CMS, DNS, SSL/HTTPS, SEO, 2FA/MFA, CDN, GA4, and SMTP. The rest you can look up here as needed.
Related guides
- Web basics: terms A–Z
- How the web works, in 5 minutes
- SEO: terms A–Z
- Domains & DNS: terms A–Z
- Security: terms A–Z
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