which one of these simple 2 files must i use to configure apache?

the httpd.conf is empty while apache2.conf isn't.

it atmosphere me!

The httpd.conf is made for user designs. You should not edit the apache2.conf because it might be up-to-date by future upgrades.

One more choice is to simply put your custom configuration into /etc/apache2/conf.d, all files within this directory are incorporated too.

If apache2.conf isn't empty, and httpd.conf is empty, you need to most likely use apache2.conf -)

However I suppose that certain includes another (which among individuals is stored purely for backward compatibility reasons) -- so, it should not change much.


Still, if you wish to add something, just like a new VirtualHost : can there be not another sub-directory, that you could put your file, and also have it incorporated ?

It might most likely be considered a better solution : you wouldn't customize the default file -- which may simplify updates.

apache2.conf includes httpd.conf:

a@test$:/etc/apache2$ cat apache2.conf | grep httpd.conf 
Include /etc/apache2/httpd.conf

I believe that httpd.conf is deprecated, but simply left inside for conservative people to ensure that they find they way around... :)

EDIT:

After reading through Rob's answer, Used to do a much better grep:

a@test:/etc/apache2$ grep -C 1 httpd.conf apache2.conf 
# Include all the user configurations:
Include /etc/apache2/httpd.conf

User designs it's...

These aren't your only options. On Ubuntu/Debian, Apache also processes all of the files in /etc/apache2/sites-enabled/ (which should be symlinks to files in sites-available/ directory, handled through the a2ensite and a2dissite programs)

You are meant to begin using these sites for VirtualHosts.