netfilter vs. iptables

[Jessica Koeppel]

Hello -please pardon my complete ignorance at this time. Don't worry,
I learn quickly. I'm just quite new to packet filtering under linux.

I was asked by my boss to set up some ipchains. A friend who knows more
about such things suggested I look at netfilter, since this is newer.
So I started in, and mentioned I was working with "iptables", and he
said that while iptables was newer than ipchains, that I really wanted
netfilter, as this was newest and best. But everything I look at that's
related to netfilter has me using iptables. 

So.. what's the relationship between "netfilter" and "iptables"?

Thanks,
--jessica