magnitude vs importance

magnitude and importance both are nouns.

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

As nouns, importance is a hypernym of magnitude; that is, importance is a word with a broader meaning than magnitude:

magnitude (noun)	importance (noun)
the property of relative size or extent (whether large or small)	the quality of being important and worthy of note
relative importance	a prominent status
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