If you were naive like me and you thought that the terms are interchangeable ... apparently they are not.

I have three rolls of filament. Shaxon's "fluorescent green" ABS and PLA, and MG's "glow-in-the-dark green" ABS.

By daylight, they look pretty much the same, and I noticed that Shaxon prints weren't all that glowy, but now I finally got around to test them side by side.

MG's "glow in the dark" stuff glows nicely if you move it into a dark room after sitting in the sun or even after a period of time under a daylight-spectrum, ahem, fluorescent lamp.

Shaxon's stuff does not glow in the dark. Like, at all.

And, strictly speaking, this is correct. Because the dictionary/textbook definition of "fluorescent" means "glowing at a certain frequency when hit by a light at a higher frequency". Presumably, Shaxon's filament would glow green under a UV light. (Can't test that part, since I don't have a UV light.)