Wikipedia
The Whoniverse is the non-narrative name given to the fictional setting of the television series Doctor Who, Torchwood, The Sarah Jane Adventures and Class as well as other related media. The word, a portmanteau of the words "Who" and "universe", has also been used to describe the show's production and fanbase.
The term is used to link characters, ideas or items which are seen across multiple productions, such as Sarah Jane Smith from Doctor Who, K-9 and Company (1981) and The Sarah Jane Adventures (2007-2011), Jack Harkness from Doctor Who and Torchwood as well as K-9 from Doctor Who, K-9 and Company, The Sarah Jane Adventures, and K-9.
Unlike the owners of other science fiction franchises, the BBC takes no position on canon, and recent producers of the show have expressed distaste for the idea. The term has recently begun to appear in mainstream press coverage following the popular success of the 2005 Doctor Who revival.