Meaning of the word duality in English

What does duality mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

duality

US /duːˈæl.ə.t̬i/
UK /dʒuːˈæl.ə.ti/

Noun

the state of having two parts, often opposing or contrasting

Example:
The novel explores the duality of good and evil.
There's a constant duality in his personality.