The term "Canon" denotes the primary continuity of a narrative, as well as additional material established as "official" in some capacity. It is often contrasted with, or used as the basis for, works of fanfiction and other fanworks, which are not considered canonical.
In the case of South Park, the primary canon consists of the theatrical film and all episodes, excluding much of "City on the Edge of Forever", and "Pip", which takes place in Victorian England, although some elements often reappear in fanon.
The canonicity of the original Spirit of Christmas shorts, and the episode "Terrance and Phillip in Not Without My Anus" is disputable, as the events have been referenced despite obvious narrative contradictions.
Canon Pairings are those that have been mentioned or shown in the official TV Program and associated film. For example, the pairing Stendy (Wendy Testaburger and Stan Marsh) is considered a canonical pairing.
Matt and Trey indicated upon the announcement of the game "South Park: The Fractured But Whole" that they considered the previous game "South Park: The Stick of Truth", to be canon to the series and suggested that the character Douchebag may be referenced in future episodes. The original game was relatively compatible with the show's canon, not showcasing many contradictions not dramatic developments, and ended with a relative reset.
During marketing for the second game, Matt and Trey frequently claimed it took place "the next day" after the first, despite acknowledging changes in the previous two seasons of the series between the games' releases, such as Principal Victoria's removal and the fact that Tweek and Craig became a couple. This inconsistency lead to game developer Jason Schroeder summarizing South Park Canon by claiming "It doesn't matter. If [Matt and Trey] need it for the plot, that space exists."
A number of inconsistencies in the second game, including errors in character names, as well as a lack of reference to the games' events in the show, such as the differences in the Gentics laboratory, the state of Stan and Wendy's relationship after season 20, and the level of racism among the Police, have lead to some fans viewing the games as a parallel timeline from the show itself.
Since "Go Fund Yourself" aired, the show has used a variation of the map created for "South Park: The Stick of Truth" in distance shots to represent the town, featuring a few small additional buildings. During the same season, as in the game, Jimbo's Guns was depicted next to City Wok - however, the map was revised the next season to include Whole Foods and other ShiTpaTown locations, and Jimbo's Guns was moved elsewhere to make room for new buildings on each side of City Wok, including a new version of Skeeter's Bar. During seasons 20 and 21, the Peppermint Hippo was later made visible behind the Police Department building, as depicted in the second game.
In another instance, for gameplay reasons, buildings are only shown on one side of Main Street, as well as Avenue des los Mexicanos and the Business District, and the ingame animation reflects this, depicting buildings on one side of each street. However, the show animation continues to depict buildings on both sides of each street, including a Red Lobster opposite City Wok. None of these buildings are visible on maps or inperson ingame.
These elements showcase that while the game locations are taken into consideration when designing the show, the town's layout remains fluid as needed for storyline purposes.