Saved by the Bell: The College Years is a sequel

Sequel

A sequel is a narrative, documental, or other work of literature, film, theatre, or music that continues the story of or expands upon issues presented in some previous work...

 to the Saved by the Bell

Saved by the Bell

Saved by the Bell is an American television sitcom that aired between 1989 and 1993. The series is a retooled version of the 1988 series Good Morning, Miss Bliss, which was itself later folded into the history of Saved by the Bell...

series which ran from September 14, 1993 (though the original pilot aired on May 22, 1993) to February 8, 1994, lasting one season. It was the third incarnation of the franchise.
In Saved by the Bell: The College Years, the cast dealt with college life at the fictional California University (a thinly veiled UC Berkeley

University of California, Berkeley

The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...

, Zack having referenced in the first episode that San Francisco was "Right across the bridge," and Kelly stating in "Wedding Plans" that "Reno is just three hours away.") The show's premise was very similar to the original Saved by the Bell series, with the six characters getting into different situations each week while remaining under the watchful eye of their resident director and later the Dean of Students.

Originally, the six main characters on The College Years were Zack Morris, A.C.