smocking vs embroidery

smocking and embroidery both are nouns.

Word	Noun	Adjective	Verb	Adverb
smocking	Yes	No	No	No
embroidery	Yes	No	No	No

As nouns, embroidery is a hypernym of smocking; that is, embroidery is a word with a broader meaning than smocking:

smocking: embroidery consisting of ornamental needlework on a garment that is made by gathering the cloth tightly in stitches
embroidery: decorative needlework

Other hypernyms of smocking include fancywork.

smocking (noun)	embroidery (noun)
embroidery consisting of ornamental needlework on a garment that is made by gathering the cloth tightly in stitches	decorative needlework
	elaboration of an interpretation by the use of decorative (sometimes fictitious) detail