cross-stitch vs sewing stitch

cross-stitch and sewing stitch both are nouns.

Word	Noun	Adjective	Verb	Adverb
cross-stitch	Yes	No	No	No
sewing stitch	Yes	No	No	No

As nouns, sewing stitch is a hypernym of cross-stitch; that is, sewing stitch is a word with a broader meaning than cross-stitch:

cross-stitch: two stitches forming a cross or X
sewing stitch: a stitch made with thread and a threaded sewing needle through fabric or leather

Other hypernyms of cross-stitch include embroidery stitch.

cross-stitch (noun)	sewing stitch (noun)
embroidery done with pairs of stitches that cross each other	a stitch made with thread and a threaded sewing needle through fabric or leather
two stitches forming a cross or X