Definition - What does Headphones mean?
Headphones are a hardware device that can be plugged into a computer, laptop, smartphone, mp3 player or other device to privately listen to audio without disturbing anyone in the vicinity. They are plug-and-play devices and do not require any sort of installation before use.
Headphones are also known as earphones, or depending on the style, earbuds.
Techopedia explains Headphones
Headphones are a pair of small speakers used for listening to sound from a computer, music player or other such electronic device. Headphones originally consisted of one speaker for each ear, connected by a band over the head. While this style is still in use, modern headphones are also available in a much smaller format that is inserted into the ear, and commonly called earbuds. Modern-day headphones can be either wireless or wired.
Headphones are designed in contrast to loudspeakers that produce sound that can be heard by anyone in the area. First created in 1910 by the U.S. Navy, early headphones were simple and were used as an earpiece device without complicated electronics.