Progressions are often written with Roman numerals relative to the key. I–V–vi–IV is the four-chord loop behind countless pop songs; ii–V–I is the backbone of jazz; I–IV–V is the basis of the 12-bar blues.
The progression sets much of a track’s emotional direction. Moving to the vi chord adds a bittersweet tint; a borrowed chord from the parallel minor adds drama. Many modern tracks loop a short progression and create interest through arrangement instead.
Using it in a prompt
You can describe a progression by feel ("bittersweet four-chord loop") or name it ("ii–V–I jazz progression"). Asking for "9th chords" or "gospel passing chords" changes the colour more than the order.