Some Questions.

I've just got a few questions...

What is Steam?

And what is the Eastern Front chat that people keep talking about? I'd like to participate :D

By Steam I presume you mean the game store?  They explain it themselves well, so here's the linkie:
http://store.steampowered.com/about/

Sorry I don't know about the chat, so will leave that for someone more knowledgeable than I to answer.

Cheers !

Eastern Front Teamspeak

Voice chat called Teamspeak. :)