Every version of South Park — the films & series, compared across media.
South Park started as an animated TV series following four irreverent grade-schoolers in the quiet, dysfunctional Colorado town of the same name. That world and those characters later moved to the cinema, taking the same anarchic premise into feature-film form. These two versions — television series and theatrical film — each find their own shape for the same characters and setting.
Yes — South Park: Bigger, Longer & Uncut is a feature film based directly on the animated TV series South Park, featuring the same characters and setting.
There are two versions covered here: the original animated TV series South Park (1997) and the theatrical feature film South Park: Bigger, Longer & Uncut (1999).
The film South Park: Bigger, Longer & Uncut builds on the world of the TV series South Park, so watching the series first will give you fuller context for the characters and setting.