substitution vs permutation

substitution and permutation both are nouns.

Word	Noun	Adjective	Verb	Adverb
substitution	Yes	No	No	No
permutation	Yes	No	No	No

As nouns, substitution and permutation are synonyms defined as:

substitution and permutation: an event in which one thing is substituted for another

Other synonyms of substitution include replacement, switch, transposition.

substitution (noun)	permutation (noun)
the act of putting one thing or person in the place of another:	complete change in character or condition
an event in which one thing is substituted for another	the act of changing the arrangement of a given number of elements
	act of changing the lineal order of objects in a group
	an event in which one thing is substituted for another