# Modules

URL: https://zerodev.ca/docs/prism/extensions

> The modules that ship with Prism and how to turn them on and off.



Everything Prism does beyond starting up comes from a module. Each module is a folder in `modules/`. Prism loads every folder with a `main.js` when it starts.

| Module                              | What it adds                                                         |
| ----------------------------------- | -------------------------------------------------------------------- |
| Core                                | Products, licenses, downloads, checkout, users and roles. Always on. |
| [Kora](/docs/prism/extensions/kora) | Issues [Kora](/docs/kora) licenses when a linked product is bought.  |

## Turning Modules On and Off

Under **System > Modules**, switch a module off to stop it. Its pages, routes and settings disappear and its routes answer `404`. Core cannot be turned off.

A module that fails to load is marked **Failed** on the Modules page and the Overview. The others keep running. The console shows why it failed.

## Adding a Module

Copy the module's folder into `modules/` and restart Prism. Any npm packages it needs are installed on start.

To write your own, see the [Developer Documentation](/docs/prism/developer-documentation).