See: Light/Classic for more information
Light is a mechanic in dark levels that allows you to see. Dark levels are pitch black so portable or fixed light sources enable the Spelunker to navigate the level safely.
The provided sorce of light is the torch . A torch is provided the begining of a dark level, and it helps you see through the level just a bit more. If it goes into water, its flame goes out, which can be relit at a lit torch on the wall sconce. The field of view diminishes the further away the Spelunker is from the source of light.
Light is also provided by some traps, torch sconces, lanterns entities and weapons.