# E-commerce glossary

> Thirty-five short definitions, written for a merchant reading a quote, an audit report or a message from a supplier and stumbling on a word. Each page says what the term means, where it shows up on a real shop, and what happens when that thing goes wrong.

- Source canonique : [https://allaux.fr/en/glossaire](https://allaux.fr/en/glossaire)
- Langue : EN
- Dernière mise à jour : 2026-08-03

## Who this glossary is for

People rarely land here out of curiosity. They land here because a quote mentions an override, because a host talks about TTFB, because an audit complains about a missing canonical tag, or because a developer answered "it's the cache" without saying which one. Technical vocabulary is not decorative: while it stays vague, there is no way to tell whether what is being proposed answers the problem.

These definitions assume nothing and try to impress no one. They stay deliberately short: the point is to understand a word in a minute and go back to the conversation you were having, not to sit through a computing course.

## How the glossary is organised

The thirty-three entries are listed alphabetically, but they fall into five natural families. Shop vocabulary: back office and front office, slug, permalink, checkout funnel, variation, product attribute, module. Server and data vocabulary: DNS, SSL/TLS, CDN, FTP/SFTP, cron, database and index, SQL query, serialisation, webhook, REST API.

Then performance: cache, TTFB, LCP, Core Web Vitals. Search: canonical, hreflang, sitemap, robots.txt, 301 redirect, migration. And finally development and diagnosis: 500 error, debug mode, hook, override, child theme, payment gateway. If you don't know which family to look in, start from the word you read: each definition links to the neighbouring terms it relies on.

## Why this vocabulary matters when you talk to a supplier

One example makes the case. "Clear the cache" means nothing until you say which one: a shop commonly stacks four — the platform's application cache, PHP's opcode cache, a module or intermediate server cache, and the visitor's browser cache. Clearing the first touches none of the other three. A great many "my change isn't showing" reports come from exactly that confusion, and one precise question settles the discussion.

The same goes for module, extension and plugin, which name the same idea on three different platforms, or for override, which on PrestaShop means a specific file under override/ and not any change to the code. Knowing what a word covers lets you ask the deciding question: does the proposed work touch the core, the theme or a module, and what happens at the next update.

An understandable quote is not a simplified quote: it is one whose every line you can check. That is what this glossary is for.

## Four definitions to read first

- **Cache** — The different cache layers on a shop, what each one stores, and which to clear for a given symptom. ([/glossaire/cache](/glossaire/cache))
- **Hook** — The attachment point that lets a module add behaviour without changing the platform core. ([/glossaire/hook](/glossaire/hook))
- **Override** — Overriding a core class: what it allows, what it breaks, and why two modules can fight over one. ([/glossaire/override](/glossaire/override))
- **301 redirect** — The permanent redirect, the basic tool of any rebuild or migration that doesn't want to lose its rankings. ([/glossaire/redirection-301](/glossaire/redirection-301))

## A word missing?

> This glossary covers the vocabulary that actually comes up in conversations about a PrestaShop, WooCommerce or Shopify shop. It does not set out to define all of computing: the terms kept are those whose misunderstanding costs something.

## FAQ

### Do these definitions apply to both PrestaShop and WooCommerce?

Most terms are common to both platforms, and often to Shopify too. Where a notion takes a specific meaning on one of them — hook, override and child theme do — the definition says so and gives the equivalent elsewhere.

### Do I need this vocabulary to run my shop?

Not for day-to-day running. But to judge a technical proposal, yes: it is the difference between accepting a quote and understanding it. A dozen terms cover most conversations.

### Are the definitions enough to do the work myself?

No, and that is not their job. They explain what a thing is, not how to handle it. Where a procedure exists, the definition links to the matching guide, which gives the steps.

### Why are the definitions so short?

Because a glossary is read in passing, usually in the middle of reading something else. A definition that takes ten minutes never gets read. The detail lives in the guides, which are written to be read end to end.