What are `*.mgd.php` files for?

Question

Browsing through a civix generated file I see it globbing for *.mgd.php files?

What are these files all about then??

Answer 1

So a little research takes me to Totten's blog where he lays out the rational for splitting out entity definitions into seperate PHP files.

The full definition of the array format is laid out in the hook_civicrm_managed guide and an example .mgd.php file is here