microscope slide vs sheet glass

microscope slide and sheet glass both are nouns.

Word	Noun	Adjective	Verb	Adverb
microscope slide	Yes	No	No	No
sheet glass	Yes	No	No	No

As nouns, sheet glass is a hypernym of microscope slide; that is, sheet glass is a word with a broader meaning than microscope slide:

microscope slide: a small flat rectangular piece of glass on which specimens can be mounted for microscopic study
sheet glass: glass formed into large thin sheets

Other hypernyms of microscope slide include plate glass.

microscope slide (noun)	sheet glass (noun)
a small flat rectangular piece of glass on which specimens can be mounted for microscopic study	glass formed into large thin sheets