飘动 describes lightweight things moving with the wind or current — flags, hair, leaves, ribbons, smoke. Compare with 飘 alone (often momentary), 飘扬 (piāoyáng, more triumphant — "flag flying high"), and 飘荡 (piāodàng, suggests aimless drifting).
memory
飘 (drift in air) + 动 (move) — "to drift-move". The 风 wind component on the right side of 飘 is a built-in reminder: this verb is for things moved by wind or air.