The so-called monitor headphones are headphones with a more real effect, that is, high-fidelity headphones, ordinary headphones often have timbre modifications in order to sound good, such as koss's PP bass is super strong, and Audio-Technica's headphones are often delicate in treble, and professional recording does not allow such modifications, so to use headphones without modification at all, it is called monitoring headphones, and audiophiles also call this sound style of audiophile headphones as monitor headphones.