The Big 8 (previously the Big 7) are a group of newsgroup hierarchies established after the Great Renaming, a restructuring of Usenet that took place in 1987. These hierarchies are managed by the Big 8 Management Board. Groups are added through a process of nomination, discussion, and voting.
History
The original seven hierarchies were comp.*.
In April 1995, when Usenet traffic grew significantly, humanities.* was introduced, and it and the seven hierarchies created by the Renaming make up today's so-called "Big 8".
References
Big 8 (Usenet) Wikipedia(Text) CC BY-SA