reduction vs decrease

reduction and decrease both are nouns.

Word	Noun	Adjective	Verb	Adverb
reduction	Yes	No	No	No
decrease	Yes	No	Yes	No

As nouns, reduction and decrease are synonyms defined as:

Other synonyms of reduction include diminution, step-down.

reduction (noun)	decrease (noun)
the act of decreasing or reducing something	the act of decreasing or reducing something
the act of reducing complexity	the amount by which something decreases
any process in which electrons are added to an atom or ion (as by removing oxygen or adding hydrogen); always occurs accompanied by oxidation of the reducing agent	a change downward
	a process of becoming smaller or shorter

reduction (verb)	decrease (verb)
	decrease in size, extent, or range
	make become smaller