stitch vs sewing stitch

stitch and sewing stitch both are nouns.

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

As nouns, sewing stitch is a hyponym of stitch; that is, sewing stitch is a word with a more specific, narrower meaning than stitch:

stitch: a link or loop or knot made by an implement in knitting, crocheting, embroidery, or sewing
sewing stitch: a stitch made with thread and a threaded sewing needle through fabric or leather

Other hyponyms of stitch include crochet stitch, knitting stitch, embroidery stitch.

stitch (noun)	sewing stitch (noun)
a link or loop or knot made by an implement in knitting, crocheting, embroidery, or sewing	a stitch made with thread and a threaded sewing needle through fabric or leather
a sharp spasm of pain in the side resulting from running

stitch (verb)	sewing stitch (verb)
fasten by sewing; do needlework