What is the difference between privapp-permissions.xml in system/etc/permissions and default-permissions.xml in system/etc/default-permissions?

Question

What is the difference between privapp-permissions.xml in system/etc/permissions and default-permissions.xml in system/etc/default-permissions?

For refernce: https://github.com/opengapps/opengapps/issues/518#issuecomment-355230967

The link didn't understand properly.

Answer 1

1. Every private permissions used by apps in /system/priv-app/ should be put in privapp-permissions.xml.
2. The dangerous permissions used by apps in /system/ can be granted by default by system/etc/default-permissions.

private permissions are permissions declared in platfrom with system|signatured flags. dangerous permissions are runtime permissions should be granted by users.