Half Step

In the F Major Scale, the third scale degree is the note A.

The fourth scale degree is the note B Flat, which is one step higher than the note A.

But not all steps are the same distance apart on the fretboard.

In our scale, the note A is on fret number 2, and the note B Flat is on fret number 3.

The two successive pitches are one fret apart; this difference in pitch is called a Half Step.