also: こんせき
noun
past and present; ancient and modern
Often used in literary or historical contexts to contrast old times with the present. Common in set phrases like 今昔の感に堪えない (deeply moved by the contrast between past and present).
この町の今昔を写真で比較する展示会が開かれた。
An exhibition was held comparing the past and present of this town through photographs.
彼
He said he was deeply moved by the contrast between past and present.