Actually that is a common misconception. A fret is a metal strip on the fingerboard. But nowadays it is common to use the noun fret as a verb i.e. 'to fret' meaning 'hold the string down behind the fret'. Therefore many guitarists have now come to refer to the space between the metal strips as a fret.
Originally Posted by anshphenomenon
Since the creation of the Internet, the Earth's rotation has been fueled, primarily, by the collective spinning of English teachers in their graves. (QDB #754533)