real time vs time period

real time and time period both are nouns.

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

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

real time: (computer science) the time it takes for a process under computer control to occur
time period: an amount of time

Other hypernyms of real time include period, period of time.

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

Other hypernyms of real time include period, period of time.

real time (noun)	time period (noun)
(computer science) the time it takes for a process under computer control to occur	an amount of time
the actual time that it takes a process to occur