year vs period

year and period both are nouns.

Word	Noun	Adjective	Verb	Adverb
year	Yes	No	No	No
period	Yes	No	No	No

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

year: the period of time that it takes for a planet (as, e.g., Earth or Mars) to make a complete revolution around the sun
period: an amount of time

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

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

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

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

year: a period of time occupying a regular part of a calendar year that is used for some particular activity
period: an amount of time

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

year (noun)	period (noun)
a body of students who graduate together	a punctuation mark (.) placed at the end of a declarative sentence to indicate a full stop or after abbreviations
the period of time that it takes for a planet (as, e.g., Earth or Mars) to make a complete revolution around the sun	the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause
a period of time containing 365 (or 366) days	an amount of time
a period of time occupying a regular part of a calendar year that is used for some particular activity	the interval taken to complete one cycle of a regularly repeating phenomenon
	a unit of geological time during which a system of rocks formed
	the end or completion of something
	(ice hockey) one of three divisions into which play is divided in hockey games