Originally Posted by ktbb

In my experience, paper piecing is done for blocks with a very specific pattern where the pattern is printed on the paper and you follow exactly where stitching lines are drawn. AFter piecing small sections, they are combined to get the final block and the paper is taken out. Foundation piecing is more general - while you may end up with a pattern, it's usually less detailed - usually strips or squares/rectangles that are stitched to the foundation sequentially to form a larger, simple shape. The foundation can be anything - paper, or fabric - and if it's fabric, its left in. In short, paper piecing is foundation piecing, but foundation piecing is not alway paper piecing....just like a square is always a rectangle but a rectangle is not always a square....does that make sense?

There is also foundation fabric that has a stitching template printed on it that is used in foundation piecing.