Does a group message cost extra on an iPhone?

So I have been group messaging a lot (messaging like 2 people in the same conversation/text). Does that cost extra or count as a picture message? I really need to know. I just got my new iPhone 4S and I'm just not sure. I don't want to get any extra charges. I have Verizon if that matters!

No it doesn't. I would know because I'm 15, so I text all the time. I do group texts a lot too, I haven't had to pay extra.