Steam-a-Seam 2 Lite is a form of fusible webbing, but think of it as a sheet of paper backed fabric glue, which melts when heated. Fantastic for appliqué of any kind. Different consistency to Bondaweb, with a stronger bond and a stiffer feel. It also is more likely to ‘gunk’ up your sewing machine needle, but this can be avoided by using anti-glue or titanium needles.
Why use it with these disadvantages? It sticks before you iron it, making complicated appliqués easier and is repositionable. It also has a very strong bond, so less stitching is required to hold it in place.