A Patchwork or "pieced work" is a form of needlework that involves sewing together pieces of fabric into a larger design. The larger design is usually based on repeat patterns built up with different colored shapes. These shapes are carefully measured and cut, straight-sided, basic geometric shapes making them easy to piece together. Precise joining makes for patchwork that lies flat without puckers.
When used to make a quilt, this larger patchwork or pieced design becomes the "top" of a three layered quilt, the middle layer being the batting, and the bottom layer the backing. To keep the batting from shifting a patchwork or pieced quilt is often quilted by hand or machine using a running stitch which can outline the individual shapes that make up the pieced top, or the quilting stitches can be random or highly ordered overall patterns that contrast with the patchwork composition.
From Wikipedia
