# Managing modules

![Screenshot: modules](../_images/screenshots/modules.svg)


The **Modules** page (`/modules`, *"Manage custom modules and addon
sources"*) is scoped per-instance — start by selecting which ERP instance
you're configuring, then:

- View **Assigned Modules** already installed on it
- **Add Module** from the catalog

Modules here are distinct from *addon sources* (configured under
[Settings](settings.md)) — an addon source is where custom module code
comes from (typically a Git repo); assigning/installing is the separate
step covered on this page. See
[Architecture § Custom addons](../developer/architecture.md) for why
that split exists.