Teamwork web development

Today i'm trying to find a way, to teamwork in Web development. I'm trying to figure out a way a few people can code in the same files at the same time, and basicly editing the website in real time. So when we save our changes, the site will update right away. As for IDE's we're all using Microsoft Visual Studio, or Adobe Dreamweaver. I have heard about GIT, but when using GIT, are you changing the site in real time?

Thanks in advance