pep talk vs exhortation

pep talk and exhortation both are nouns.

Word	Noun	Adjective	Verb	Adverb
pep talk	Yes	No	No	No
exhortation	Yes	No	No	No

As nouns, exhortation is a hypernym of pep talk; that is, exhortation is a word with a broader meaning than pep talk:

pep talk: a speech of exhortation attempting to instill enthusiasm and determination in a team or staff
exhortation: the act of exhorting; an earnest attempt at persuasion

Other hypernyms of pep talk include incitement.

pep talk (noun)	exhortation (noun)
a speech of exhortation attempting to instill enthusiasm and determination in a team or staff	the act of exhorting; an earnest attempt at persuasion
	a communication intended to urge or persuade the recipients to take some action