Marking location and time. The difference depends on static vs dynamic verbs.
Usage
•
에 (e): Time, Destination ("to"), or Static Location ("at/in" with stay/exist).
•
에서 (eseo): Location where an action happens, or Source ("from").
In Context
학교에 가요.
I go to school.
카페에서 공부해요.
I study at the cafe.