modern history
Refers to the historical period from roughly the Meiji era onward, or the academic field studying that period.
He is majoring in modern history at university.
This museum has an exhibition on modern history.
歴史 is the general term for 'history', while 近代史 specifically means 'modern history'.
Compound of 近代 (きんだい, 'modern era') and 史 (し, 'history').