A “chord” on guitar means multiple strings being played – normally all at once, but can also be played as an arpeggio (play through all the strings in the chordA "chord" on guitar means multiple strings being played, one string at a time.)
A chordA "chord" on guitar means multiple strings being played can be played with no strings fretted, one string fretted or multiple strings fretted. (“Fretted” refers to holding down one or more strings at a particular position on the fretboard.)