The Korean particle "에서" is used to indicate the location where an action takes place. It is often translated as "at" or "in" in English. For example, in the sentence "학교에서 공부해요" (I study at school), "에서" shows that the action of studying occurs at the school. Additionally, "에서" can also denote the starting point of an action, especially in movement verbs. For instance, in "집에서 나가요" (I leave from home), "에서" indicates that the action of leaving begins at the home. This particle is essential for expressing location and direction in Korean sentences.