I've been able to study **5 Magento shops** in the last weeks. And I've noticed a mess in module management.

I've seen 2 places where the `modules/extensions` appear:

- MagentoConnect page: where you can see the module name, description, version and you are able to uninstall or upgrade
- `/app/etc/modules` directory: where the main `XML` of the module appear

**My questions about modules:**

1) Why do I see some modules appearing in **`"etc"`** directory, but they don't appear in Magento Connect page ?

2) In that cases, how can I uninstall a module?

3) And how can I know which files are related with that module ?

Thank you !