semester vs time period

semester and time period both are nouns.

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

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

Other hypernyms of semester include period, period of time.

semester (noun)	time period (noun)
one of two divisions of an academic year	an amount of time
half a year; a period of 6 months