"Coverlet" is a term used to describe the top covering placed on a bed when it is made -- a bedspread. A quilt is a blanket of any size made by decoratively stitching together a top, a bottom and a middle layer of batting, or filling. Some quilts are coverlets, but not all coverlets are quilts.
Coverlets and quilts both can be mainly for warmth, decoration or both. Coverlets are used exclusively to top beds, while quilts can also be used as lap rugs or wall hangings.
To be designated a coverlet, the fabric must cover the entire surface of the bed and hang down the sides, although it doesn't have to reach the floor. Quilts can be any size, from doll blankets to massive works of art that cover an entire wall.
Coverlet fabrics range from light chenille, such as in children's bedspreads, to heavy, suede-like cottons. Quilts are made of fabrics such as cotton, silk or wool that have a loose enough weave to allow stitching through several layers of material.
While technically a coverlet is any bed covering, the term usually means a lighter, thinner covering -- even a single layer of chintz -- rather than a thick duvet or comforter. Because a quilt must have at least two fabric layers as well as a filling, it has more heft and less flexibility than a coverlet.
Coverlets can be simple, plain, one-color bedspreads or elaborately woven or embroidered designs. While early and pioneer quilts could be hodgepodges of scraps thrown together merely for warmth, most modern quilts are made with an eye to design.