Is there a name for this kind of lighting?

I was watching a movie, and the actor turned on a light. The light coming from it was clearly that of the light the actor turned on, not like when an actor lights a match and lights that are out of frame provide the actual light.

Is there a word for these types of lighting, off screen, on screen or something? Any other interesting movie lighting terms or tricks are of interest to me as well.

I’m not sure if this is an unusual use of the word, as it is usually applied to sounds, but the term “diegetic” covers this concept. For example, when they add soundtrack music by just overlaying a song on a scene, that’s non-diegetic, but when a character puts a quarter in a jukebox and the music is supposed to be coming from the jukebox, that’s diegetic music.

The stagecraft term is to call the light a ‘practical’ lamp (one that actually works, as opposed to a ‘prop’, one that is strictly a stage property).

Props don’t have to be non-functional. Any prop that an actor actually interacts with is called a “hero prop”. I’m not sure if you’d apply it to a light, but I don’t see why not.

This is already fascinating. If the GQ rules permit it, I’d love to hear more of the same, no matter the area of film that it includes.
Thanks guys!

If your interest extends to stage lighting, you may want to look up A Method of Lighting the Stage by Stanley McCandless.

Stage lighting is different from film/tv lighting, but some of the same concepts apply.