mode vs signature

mode and signature both are nouns.

Word	Noun	Adjective	Verb	Adverb
mode	Yes	No	No	No
signature	Yes	No	No	No

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

mode (noun)	signature (noun)
how something is done or how it happens	a distinguishing style
the most frequent value of a random variable	your name written in your own handwriting
any of various fixed orders of the various diatonic notes within an octave	a sheet with several pages printed on it; it folds to page size and is bound with other signatures to form a book
a classification of propositions on the basis of whether they claim necessity or possibility or impossibility	the sharps or flats that follow the clef and indicate the key
verb inflections that express how the action or state is conceived by the speaker	a melody used to identify a performer or a dance band or radio/tv program
a particular functioning condition or arrangement