resource vs sustenance

resource and sustenance both are nouns.

Word	Noun	Adjective	Verb	Adverb
resource	Yes	No	No	No
sustenance	Yes	No	No	No

As nouns, sustenance is a hyponym of resource; that is, sustenance is a word with a more specific, narrower meaning than resource:

resource: available source of wealth; a new or reserve supply that can be drawn upon when needed
sustenance: the financial means whereby one lives

resource (noun)	sustenance (noun)
a source of aid or support that may be drawn upon when needed	the act of sustaining life by food or providing a means of subsistence
the ability to deal resourcefully with unusual problems	a source of materials to nourish the body
available source of wealth; a new or reserve supply that can be drawn upon when needed	the financial means whereby one lives