WHIZ is the fictional radio station for which Billy Batson, who is also the superhero Captain Marvel, works. It appears in various Captain Marvel stories published by Fawcett Comics and DC Comics, the current publishers/owners of the Fawcett characters.
WHIZ, named after Captain Marvel's original magazine of publication, Whiz Comics, is located in fictional Fawcett City, and is managed by Billy's boss, Sterling Morris.