Is there any extra layer consuming resources in native stacks ?

Hello,

I'm entirely new to BitNami stacks and there is one fact I need to know before using the stacks for production purposes:

When running VMware virutal machine stacks there is a program/layer running in the background, which emulates hardware and uses up resources for that.

How about the native stacks ?

1. Is there any extra layer or program between the installed programs (apache, perl, ruby, ...) and the operating system or is the installation similar to a normal installation of the programs on the computer?
2. Is there any additional consumption of resources compared to a manual installation (without the BitNami stack)?

Thanks in advance for the help !

Regards, Tavos