hair care vs shampoo

hair care and shampoo both are nouns.

Word	Noun	Adjective	Verb	Adverb
hair care	Yes	No	No	No
shampoo	Yes	No	Yes	No

As nouns, shampoo is a hyponym of hair care; that is, shampoo is a word with a more specific, narrower meaning than hair care:

hair care: care for the hair: the activity of washing or cutting or curling or arranging the hair
shampoo: the act of washing your hair with shampoo

Other hyponyms of hair care include brush, brushing, comb, combing, hairweaving.

hair care (noun)	shampoo (noun)
care for the hair: the activity of washing or cutting or curling or arranging the hair	the act of washing your hair with shampoo
	cleansing agent consisting of soaps or detergents used for washing the hair

hair care (verb)	shampoo (verb)
	use shampoo on (hair)