The Modern Quilting Guild has given this definition:
Modern quilts are primarily functional and inspired by modern design. Modern quilters work in different styles and define modern quilting in different ways, but several characteristics often appear which may help identify a modern quilt. These include, but are not limited to: the use of bold colors and prints, high contrast and graphic areas of solid color, improvisational piecing, minimalism, expansive negative space, and alternate grid work. “Modern traditionalism” or the updating of classic quilt designs is also often seen in modern quilting.(
https://www.seasonedhomemaker.com/wh...-modern-quilt/)
Traditional quilting definitions are not that easy to state in a few words but follow along the line of the following:
Traditional quilts are quilts that have been made in the past, generally before the quilting revival of the 1970s. Because of the methodology of sharing quilt patterns, the majority of these quilts are made using patchwork techniques. Most of them are made with traditional quilt blocks that are combined to make a traditional quilt and adhere to the "rules of quilting". (
https://hubpages.com/art/What-is-a-Traditional-Quilt)