backing vs backup

backing and backup both are nouns.

Word	Noun	Adjective	Verb	Adverb
backing	Yes	No	No	No
backup	Yes	No	No	No

As nouns, backing and backup are synonyms defined as:

Other synonyms of backing include championship, patronage.

backing (noun)	backup (noun)
the act of providing approval and support	the act of providing approval and support
something forming a back that is added for strengthening	(computer science) a copy of a file or directory on a separate storage device
financial resources provided to make some project possible	a musical part (vocal or instrumental) that supports or provides background for other musical parts
	someone who takes the place of another (as when things get dangerous or difficult)
	an accumulation caused by clogging or a stoppage