QQ Groups are primarily a feature of the QQ IM clien. You can categorize your friends, but you can also group your friends. These two features seem similar (you bundle friends), but groups are much more advanced. Categorized friends are just something to easily find a particular person. Groups allow you to talk to several people at once though. Each group has a group owner, optionally several administrators and then regular group members. Groups are, at the moment, primarily an IM feature, with limited and aging website.

Language

There is a very basic English version of QQ Groups: http://igroup.qq.com/en/ you first need to login with your QQ account and then you can manage your QQ groups, like change the name etc. The Chinese version of groups is more advanced, but is quite old.