raw edge machine applique you draw your design on the paper side of paper=backed fusable, iron to the wrong side of the fabric, cut out on the lines, fuse to background then stitch the edges using what ever stitch you want...no turn under, some people straight stitch them down, some zig-zag, some use a blanket stitch, what ever. there are hundreds of books and tutes out there for hand applique and lots of different techniques. trial and error works too, lots of us have learned that way.
needle turn applique, templates are used for the pieces, you add a turn under seam allowance around the piece when you cut it out. Becky Goldsmith offers some pretty clear pictures, help on their website. piece of cake quilts