[CentOS] How rc-local.service works?

Hi,

Let me cite the service file here:

[Unit]
Description=/etc/rc.d/rc.local Compatibility
ConditionFileIsExecutable=/etc/rc.d/rc.local
After=network.target

[Service]
Type=forking
ExecStart=/etc/rc.d/rc.local start
TimeoutSec=0
RemainAfterExit=yes

I basically don't understand two things here:

1. What makes it run? Sure, when I make /etc/rc.d/rc.local executable,
it runs. But for all I know, for it to run some other service must
pull in it as a dependency. Am I wrong?

2. Why Type=forking?

Thanks in advance.

Regards,
Yuri