When you see the notation “sus2” after a chord the notation indicates that instead of playing the third note from the root to build a standard chord triad (1-3-5) you’d play the second note from the root note instead. For example, a standard “C” major chord would contain the notes:
C maj = C – E – G (1 3 5)
The sus2 variation would be:
sus2 = C – D – G (1 2 5)
Using sus2 variations of chords can gives your songs extra flavor that can be useful in place of a standard triad. Give it a try!