Module: definition
A module is an installable PrestaShop extension that adds or changes a store feature by hooking into hooks, without ever modifying core files.
Why it's the recommended way to extend the platform
A module lives in its own folder under modules/, with a main file that declares its name, its version and the hooks it registers with via registerHook() on install. At runtime, PrestaShop calls the module's corresponding methods, for example hookDisplayPaymentReturn to display a message after payment, without ever touching the store's native code.
This isolation is what makes modules upgrade-safe: a PrestaShop update replaces core files but leaves the modules/ folder untouched. A well-coded module therefore keeps working after a version upgrade, unlike an override, which rewrites a core class directly and can conflict with it.
For an online retailer, the distinction matters in practice when choosing a provider or an extension: a module from the official marketplace, or one built to order via hooks, is easier to evolve, to uninstall cleanly, and to audit in the event of a slowdown or a conflict with another module.
Frequently asked questions
Can a module slow down a store?
What's the difference between uninstalling and disabling a module?
Are all PrestaShop modules equal in quality?
Describe your need in one minute
A few targeted questions so I can reply with an estimate rather than another questionnaire.