What's the difference between a page and a group on facebook?

Well originally pages were just for companies, celebrities and whatnot who couldn’t have actual profiles. Groups were more about either a cause or a group that you’re a part of in real life. Pages are more about observing, groups are more about participating.

Groups are more active communities while pages are simply topics of interest you can become a fan of. This difference is becoming more and more subtle, however, as more people make each of these.