Help! What's the raglan seams?

I have all the pieces of my granddaughter’s cardigan sweater finished. There is a back, a right front, a left front, and 2 sleeves. The pattern says: Join raglan seams, but assumes that I really know which pieces make up the raglan seams. Then I have to pick up stitches all along the front and around the collar, and work in rib for awhile, making the buttonholes.

And what method will I use to sew the raglan seams, once I know what they are??

I love the way all the pieces of her sweater look, now I’m just afraid I’ll mess it up putting it together - please help!

The raglan edges are the ones that are slanted and will go from the underarm to the neck. So the top of your sleeves and the tops of your body. Use the mattress stitch. It works out loverly!!