As nouns the difference between smartphone and headphone
is that smartphone is smartphone while headphone is a listening device placed or worn in the ear, usually sold in pairs.
smartphone
English
Noun
(
en noun)
A mobile phone with more advanced features and greater computing capacity than a featurephone.
headphone
English
Noun
(
en noun)
A listening device placed or worn in the ear, usually sold in pairs
- She handed me one headphone so I could listen too.
Usage notes
Also used as a noun modifier: e.g. headphone plug, headphone socket.