Network configuration files

[Grimsrud]

What is the relationship between iwconfig, the network service
/etc/sysconfig/networks-scripts/ifcfg-eth1 and ifup?

Does the network service apply the settings in ifcfg-eth1 (incl.
/etc/sysconfig/network-scripts/keys-eth1 for wireless) with iwconfig before
it executes ifup?

I've looked at the script sources, but they are a little to complicated for
me.

Thanks