episode vs installment

episode and installment both are nouns.

Word	Noun	Adjective	Verb	Adverb
episode	Yes	No	No	No
installment	Yes	No	No	No

As nouns, episode and installment are synonyms defined as:

Other synonyms of episode include instalment.

episode (noun)	installment (noun)
film consisting of a succession of related shots that develop a given subject in a movie	the act of installing something (as equipment)
a part of a broadcast serial	a part of a broadcast serial
a brief section of a literary or dramatic work that forms part of a connected series	a part of a published serial
a happening that is distinctive in a series of related events	a payment of part of a debt; usually paid at regular intervals