a scrappy quilt is made from many, many different fabrics (scraps) instead of a 'collection' of coordinating fabrics. lots of times made from (scraps) but not necessarily...i've seen turning 20's considered scrappy because the fabrics did not (belong) to each other, but were all ... scrappy
scrap quilts are often made using (value) instead of color. there are planned scrappy...where a person is using her scraps but trying to (plan) the color-design components...or there are quilts like 1000 peramids that is made with 1000 triangles (sometimes all different)
there are some pretty good books out that deals with scrap quilting, one that comes to mind is...
"LOTS OF SCRAPS-TIME TO QUILT"