Situational comedies, or sitcoms, thrive on following a fixed group of characters and their daily routines. In most comedy TV series, there is usually one main character who's meant to hold the primary focus, even when there's an ensemble cast. The purpose of this primary character is to be the viewer's guide into the show's world or plot line.
Source：https://www.cbr.com/most-popular-side-characters-in-comedy-tv-shows/
