youth vs time period

youth and time period both are nouns.

Word	Noun	Adjective	Verb	Adverb
youth	Yes	No	No	No
time period	Yes	No	No	No

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

Other hypernyms of youth include period, period of time.

youth (noun)	time period (noun)
the freshness and vitality characteristic of a young person	an amount of time
young people collectively
a young person (especially a young man or boy)
early maturity; the state of being young or immature or inexperienced
the time of life between childhood and maturity
an early period of development