magnitude vs volume

magnitude and volume both are nouns.

Word	Noun	Adjective	Verb	Adverb
magnitude	Yes	No	No	No
volume	Yes	No	No	No

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

magnitude (noun)	volume (noun)
the property of relative size or extent (whether large or small)	physical objects consisting of a number of pages bound together
relative importance	the magnitude of sound (usually in a specified direction)
a number assigned to the ratio of two quantities; two quantities are of the same order of magnitude if one is less than 10 times as large as the other; the number of magnitudes that the quantities differ is specified to within a power of 10	the property of something that is great in magnitude
	a publication that is one of a set of several similar publications
	the amount of 3-dimensional space occupied by an object
	a relative amount