Raglan

I am knitting a raglan sleeve pattern and I have reached the point where the pattern is telling me to “sew raglan seams leaving left back raglan seam open”. I am a bit confused as to what I am exactly supposed to sew together.
Thank you for any help

The raglan seams are usually the decrease lines from the underarm to the top of the sleeve. Stitch one sleeve to the front raglan seam and the back raglan seam. Stitch the other sleeve to the front raglan seam only at this point in the directions. You’ll close the remaining seam later.

This video shows you the raglan seams. Your sleeves may not necessarily come to a point as these do.