Unless you're a music theory buff or taking AP Music Theory in school (forced or otherwise), then the only word in "diatonic circle chord progressions" that makes sense to you is "circle." But the fancy schmancy term is just an elaborate way of saying you're playing chord progressions based on the circle of fifths.
The circle of fifths shows the relationships between the twelve tones of the chromatic scale, key signatures, and major and minor keys.
In this piano lesson we'll learn about the diatonic circle chord progression and how to play it on the piano. Then you'll see how it is played on the songs "Autumn Leaves" and "I Will Survive."