rest period vs pause

rest period and pause both are nouns.

Word	Noun	Adjective	Verb	Adverb
rest period	Yes	No	No	No
pause	Yes	No	Yes	No

As nouns, pause is a hypernym of rest period; that is, pause is a word with a broader meaning than rest period:

rest period: a pause for relaxation
pause: a time interval during which there is a temporary cessation of something

Other hypernyms of rest period include break, intermission, interruption, suspension.

rest period (noun)	pause (noun)
a pause for relaxation	temporary inactivity
	a time interval during which there is a temporary cessation of something

rest period (verb)	pause (verb)
	cease an action temporarily
	interrupt temporarily an activity before continuing