noun
Refers to a physical or conceptual space under someone's control or influence, such as a nation's territory or a company's market domain.
その国は隣国の領域を侵犯した。
That country violated the neighboring country's territory.
この問題は私
This matter is outside my domain.
noun
Broadly used for any specialized field, area of activity, or abstract realm, such as academic disciplines, professional expertise, or personal interests.
彼は物理学の領域で有名だ。
He is famous in the field of physics.
それは専門外の領域です。
That is outside my area of expertise.
noun
Mathematical term for the set of input values for which a function is defined, or a connected region in a space.
この関数の定義領域は実数全体です。
The domain of this function is all real numbers.
複素平面上の領域を図示しなさい。
Illustrate the region on the complex plane.