Google Groups (formally Deja News) provides an index to all USENET discussion groups. Millions of people across the globe use discussion groups to talk about every subject of interest to everyone. Groups are like email except that the message is sent to a group email list instead of to an individual and anyone who joins the group can read the messages of that group. Hence, newsgroups provide a very natural mechanism to obtain timely relevant information on all topics. Most Web search engines maintain an index of web pages whereas newsgroup searching examines conversations past and present. Since conversations naturally include references to the Web, newsgroups are always a good place to start when looking for just about anything.

Have you ever sent an email and then wished you had worded it differently or not even sent it at all? With Google Groups you can remove a posting if you change your mind about having sent it. This can be a very useful feature.

In addition, the date of each newsgroup posting is known, since it is part of the standard that specifies the content of postings. Web pages do not have this feature. There is no method to search normal HTML Web pages based on date of authorship of the web page. For newsgroup search, one can delimit the search by a date range, providing a very valuable filter to assist finding useful results.

I use Google Groups Advanced Search. I think of a phrase which is likely to be in a conversation about the topic of interest, then enter that phrase between double quotes ("...") into the Google search form. I often find what I am looking for very quickly, sometimes within a few mouse clicks through the initial page of returned references.