labor pool vs working class

labor pool and working class both are nouns.

Word	Noun	Adjective	Verb	Adverb
labor pool	Yes	No	No	No
working class	Yes	No	No	No

As nouns, working class is a hypernym of labor pool; that is, working class is a word with a broader meaning than labor pool:

labor pool: the source of trained people from which workers can be hired
working class: a social class comprising those who do manual labor or work for wages

Other hypernyms of labor pool include labor, labour, proletariat.

labor pool (noun)	working class (noun)
the source of trained people from which workers can be hired	a social class comprising those who do manual labor or work for wages