A complete A–Z glossary of technical web and internet terms gives you a fast, structured way to understand the core concepts behind how the modern web works — from networking and security to frontend, backend, performance, SEO, and cloud infrastructure. Below is a curated, alphabetized list of essential terms with concise definitions, synthesized from authoritative web‑development and internet glossaries.
A
- A/B Testing — Comparing two versions of a webpage or feature to see which performs better.
- Accessibility — Designing sites usable by all people, including those with disabilities; guided by WCAG.
- API — Interface allowing software systems to communicate.
- ARIA — HTML attributes improving accessibility for assistive technologies.
- Autonomous System (AS) — Large network segment on the internet with a unique ASN.
B
- Backend — Server-side logic, databases, and APIs powering an application.
- Bandwidth — Maximum data transfer capacity of a network connection.
- Bounce Rate — Percentage of visitors who leave after viewing one page.
- Breadcrumbs — Hierarchical navigation showing a user’s location.
- Browser Compatibility — Ensuring consistent behavior across browsers.
C
- Cache — Temporary storage for faster data retrieval.
- Canonical URL — Preferred version of a page for SEO.
- CDN — Distributed servers delivering content closer to users.
- CMS — Software for managing website content.
- CORS — Browser security mechanism controlling cross‑domain requests.
D
- DNS — System translating domain names to IP addresses.
- Domain — Human-readable website address.
- DOM — Tree representation of HTML for scripting and rendering.
- DevOps — Practices integrating development and operations.
- Docker — Containerization platform for packaging applications.
E
- Edge Computing — Processing data near the user to reduce latency.
- ERP — Integrated business management software.
- Evergreen Content — Content that remains relevant long-term.
F
- Favicon — Small icon shown in browser tabs.
- FCP — Performance metric measuring first visible content.
- Framework — Prebuilt structure for building applications (e.g., React).
- FTP — Protocol for transferring files over a network.
G
- Git — Version control system for tracking code changes.
- GDPR — EU regulation governing data privacy.
- GraphQL — Query language for APIs.
H
- Hosting — Service providing server space for websites.
- Hreflang — Tag specifying language/region versions of pages.
- HTTPS — Secure, encrypted version of HTTP.
I
- INP — Core Web Vital measuring responsiveness.
- IP Address — Numeric identifier for devices on a network.
- ISR — Next.js method for updating static pages.
J
- JavaScript — Primary scripting language of the web.
- JSON — Lightweight data-interchange format.
- JWT — Token format for authentication.
K
- Keyword — Search term targeted for SEO.
L
- LCP — Core Web Vital measuring main content load speed.
- Lazy Loading — Loading resources only when needed.
- Landing Page — Page designed for conversions.
M
- Modem — Device converting digital/analog signals for internet access.
- Metadata — Data describing content (titles, descriptions).
N
- NAP Consistency — Matching business name/address/phone across listings.
- Network — Connected devices sharing resources.
O
- OAuth — Authorization protocol for secure delegated access.
- Open Graph — Metadata for social sharing previews.
P
- Performance — Speed and responsiveness of a site.
- Proxy Server — Intermediary server for requests.
Q
- Query String — URL parameters used to pass data.
R
- Responsive Design — Layouts adapting to screen sizes.
- REST — Architectural style for APIs.
S
- SEO — Optimizing visibility in search engines.
- SSL/TLS — Encryption protocols securing data.
- Static Site — Pre-rendered pages served without server logic.
T
- TCP/IP — Core internet communication protocols.
- TLS Certificate — Digital certificate enabling HTTPS.
U
- UI — Visual and interactive elements of a site.
- URL — Address of a web resource.
V
- Version Control — Tracking and managing code changes.
- Virtualization — Running multiple OS instances on one machine.
W
- Web Server — Software delivering web content.
- Web Vitals — Google’s key performance metrics.
X
- XML — Markup language for structured data.
- XSS — Injection attack targeting client-side scripts.
Y
- YAML — Human-readable configuration format.
- YouTube API — Interface for interacting with YouTube data.
Z
- Zero‑Day Vulnerability — Security flaw exploited before a fix exists.
- ZIP — Compressed archive format for files.
