"Martin C." wrote:
I use an NNTP client but I can't figure out what google means by 'google
groups'.

There is no such thing as a 'google group' (or is there?).

This, for example, is posted to a USENET group (or a USENET newsgroup) -
but what does google mean by "google groups"?

Google groups include Usenet, AND other ones only google does. You can set
up your own group I guess.

Greg