>>713699103
SH4 established that Silent Hill is a normally functioning town with people living there. The only abnormal thing about the town is the alternative dimension known as the "Otherworld" and a religious cult known as "The Order" (which mainly worked in secret). The otherworld dimension can be entered by people with a deep trauma, cultists who know how to open portals to it, and people with supernatural powers like Alessa or Walter who also have the ability to control the Otherworld dimension and even spread it the to other places in the world.

The Otherworld dimension adjusts its appearance and the appearance of its monsters to every traumatic person that enters it. If you overcome your trauma, then you return to a normal dimension of the town with people living there. Akira Yamaoka and Masahiro Ito even said in an old interview that Team Silent's original concept for Silent Hill 5 was about playing as a regular civilian in the town who slowly enters the Otherworld throughout the game as they experience more and more tragic events in their life