The anhemitonic form of pentatonic scale has no semitones (ex. c–d–f–g–a–c} this is the most commonly used form.
The two basic forms of pentatonic scales are:
Major Pentatonic - Consists of the 1st - 2nd - 3rd - 5th - 6th notes of a major scale.
Minor Pentatonic - Consists of the same 5 notes of a major pentatonic scale but its tonic (first note of the scale} is 3 semitones below the tonic of the major pentatonic scale. For example, the C major pentatonic (C - D - E - G - A} has the same notes as the A minor pentatonic (A - C - D - E - G} but arranged differently. The first note or tonic of the A minor pentatonic scale (=A) is 3 semitones (half steps) lower than the first note of the C major pentatonic scale (=C). It uses the 1st - minor 3rd - 4th - 5th - minor 7th notes of a scale.