era vs Caliphate

era and Caliphate both are nouns.

Word	Noun	Adjective	Verb	Adverb
era	Yes	No	No	No
Caliphate	Yes	No	No	No

era (noun)	Caliphate (noun)
a period marked by distinctive character or reckoned from a fixed point or event	the era of Islam's ascendancy from the death of Mohammed until the 13th century; some Muslims still maintain that the Muslim world must always have a calif as head of the community
a major division of geological time; an era is usually divided into two or more periods