also: こんせき
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).
An exhibition was held comparing the past and present of this town through photographs.
He said he was deeply moved by the contrast between past and present.
Looking at old photos, I'm overwhelmed by how much things have changed.
This book introduces the town by comparing its past and present.