The main difference between a quilt and a comforter lies in their construction and warmth. Quilts are typically lighter and consist of three layers: a top, batting, and a bottom layer, all stitched together. Comforters are fluffier and filled with synthetic fibers or down, making them warmer and loftier. While quilts can be used as a top layer for style or light warmth, comforters are designed to be the main blanket for warmth during sleep.