GLOSSARY

Glossary

Glossary

The words of the Web demystified, assuming no prior knowledge. Search a term or browse by category.

Fundamentals

Browser

The software that displays web pages: Chrome, Firefox, Safari, Edge.

HTTP / HTTPS

The protocol by which browser and server exchange. HTTPS is its encrypted (secure) version — the one to use everywhere today.

Internet

The worldwide network linking all computers and devices through a common language (TCP/IP).

Internet provider FAI / ISP

The company that connects you to the Internet through your router (Orange, Free, etc.).

IP address IP

The unique number identifying each connected device, like a phone number for machines.

Latency

The delay between a request and the start of the response. The lower it is, the more responsive the site feels.

Server

A computer always on that stores a website and sends it to visitors who request it.

URL URL

The full address of a web page, the one you type in the browser (e.g. https://example.com/contact).

Web (World Wide Web) WWW

The set of pages linked together, viewed in a browser. It is ONE service of the Internet, not the Internet itself.

Wi-Fi

The wireless link between your devices and your router, over a few metres. It is not the Internet, just the last link.

Building a site

CMS CMS

Content Management System: a tool to build and edit a site without coding (WordPress, etc.).

CSS CSS

The language that styles the page: colours, fonts, layout. HTML structures, CSS decorates.

DNS DNS

The directory of the Internet: it turns a domain name (example.com) into the server’s IP address.

Domain name

Your site’s readable address (example.com). Rented for ~€12/year from a registrar.

Hosting

Renting space on a server to store your site and keep it accessible 24/7.

HTML HTML

The language that structures a page’s content (headings, paragraphs, images, links).

No-code

Building a site or app without writing code, via visual tools (Wix, Webflow, Shopify).

Responsive

A site that adapts automatically to the screen: phone, tablet, desktop. Essential today.

Shared hosting

Several sites share one server. Cheap (€3–10/month), ideal to start.

Development & code

API API

An interface that lets two pieces of software talk and exchange data (showing weather, stock, a payment on your site).

Cache

A temporary copy of already-computed content, kept to serve it faster instead of redoing everything on each visit.

CDN CDN

A network of servers worldwide that delivers your site from the point closest to the visitor — hence its speed.

Database

The system that stores and organises a site's data (posts, accounts, orders) — e.g. MySQL, PostgreSQL.

Framework

A toolbox that structures and speeds up development (React, Vue for the front; Express, Laravel for the server).

Front-end / Back-end

The front is what the visitor sees (in the browser); the back is what runs on the server (data, logic).

Git

The tool that tracks code versions and enables teamwork (often via GitHub or GitLab).

Headless CMS

A "headless" content system: it manages content but does not dictate the display, delivered via API to the front-end of your choice.

Jamstack

A modern approach: a fast static site (the shell) that fetches dynamic data via APIs. JavaScript + APIs + Markup.

Node.js

Lets you run JavaScript on the server. Ideal for APIs and real-time applications.

npm

Node.js's package manager: the world's largest catalogue of reusable libraries.

Open source

Software whose code is public and freely reusable (WordPress, Linux, Astro…).

PHP PHP

A very common server-side language: it builds the pages of dynamic sites. WordPress is written in PHP.

SaaS SaaS

Software as a Service: software used online by subscription, with nothing to install (Gmail, Notion, Shopify…).

Web server

The program that receives browser requests and returns pages (Apache, Nginx, Caddy).

Webhook

An automatic "trigger": when an event occurs (a payment, a form), one service notifies another in real time via a URL.

Artificial intelligence

Artificial intelligence IA / AI

Programs able to imitate human tasks (understanding text, recognising an image, answering). Today, mostly models trained on huge amounts of data.

Deep learning

The most powerful form of machine learning, based on multi-layer "neural networks". At the heart of current AI.

General AI (AGI) AGI

A hypothetical AI as versatile as a human, able to learn anything. It does not exist yet: everything that exists is "narrow" (specialised).

Generative AI

An AI that creates new content — text, image, sound, code — from a prompt. The current wave (ChatGPT, Midjourney).

GPU GPU

The chip specialised in massively parallel computation. Built for games, it became the "fuel" for training and running AI.

Hallucination

When an AI confidently states something false but plausible. Hence the need to always verify what it produces.

LLM (language model) LLM

The engine of text assistants (ChatGPT, Claude, Mistral): trained on huge corpora, it predicts the next word to generate its answers.

Machine learning ML

The basis of modern AI: the machine learns from examples instead of following hand-written rules.

Multimodal

Describes an AI able to understand and produce several formats at once: text, image, audio, video.

Open / closed model

An "open" model (Llama, Mistral) can be downloaded and self-hosted; a "closed" model (GPT, Claude, Gemini) is only available via its service or API.

Prompt

The instruction you give the AI. The more precise it is (context, constraints, examples), the better the answer.

Token

The unit of text AI models read and produce (a word is roughly one to three tokens). It is the basis for how they are billed.

Getting found (SEO)

Core Web Vitals

Google’s metrics for a page’s speed and comfort. Poor scores push you down in results.

Google Business Profile

The free listing showing your business on Google and Maps (hours, reviews, directions). A local must-have.

Keywords

The words your customers type into Google. Your content must answer them to be found.

Local SEO

Being found for location-based searches ("plumber + town"). The #1 customer driver for a small business.

SEO SEO

The art of appearing in Google results without paying, by optimising your site and content.

Security & data

Backup

A copy of your site and data, kept separately. Essential in case of failure or hacking.

Phishing

A fake message imitating a brand to steal your credentials. Always check the sender and the address.

SSL / TLS / HTTPS TLS

The browser “padlock”: TLS (the successor of SSL) encrypts exchanges, which gives HTTPS. Mandatory and expected by visitors and Google alike.

Strong password

Long, unique and unpredictable. Use a password manager rather than reusing it everywhere.

Two-factor authentication 2FA

A 2nd proof of identity (code by SMS or app) on top of the password. The best protection for your accounts.