slum area vs shantytown

slum area and shantytown both are nouns.

Word	Noun	Adjective	Verb	Adverb
slum area	Yes	No	No	No
shantytown	Yes	No	No	No

As nouns, shantytown is a hyponym of slum area; that is, shantytown is a word with a more specific, narrower meaning than slum area:

slum area: a district of a city marked by poverty and inferior living conditions
shantytown: a city district inhabited by people living in huts and shanties

Other hyponyms of slum area include skid row.

slum area (noun)	shantytown (noun)
a district of a city marked by poverty and inferior living conditions	a city district inhabited by people living in huts and shanties