A footlight is a theatrical lighting

Stage lighting

Modern stage lighting is a flexible tool in the production of theatre, dance, opera and other performance arts. Several different types of stage lighting instruments are used in the pursuit of the various principles or goals of lighting. Stage lighting has grown considerably in recent years...

 device arranged to illuminate a stage

Stage (theatre)

In theatre or performance arts, the stage is a designated space for the performance productions. The stage serves as a space for actors or performers and a focal point for the members of the audience...

from the front edge of the stage floor in front of the curtain. Originally set in a row of hooded individual enclosures, electric footlights are presently set in troughs cross the edge of the stage so that they are not visible to the audience. An indirect footlight uses a light aimed at a reflecting surface to diffuse the illumination.