The particle "에" in Korean is used to indicate a location or a point in time. It can denote where an action takes place or when an event occurs. For example, in the sentence "학교에 가요" (I go to 학교), "에" shows the destination of the action. Additionally, "에" can express a purpose or a target. For instance, in "선물을 친구에게 줘요" (I give a gift to 친구), "에" helps clarify the recipient of the action. Understanding "에" is essential for constructing clear and accurate sentences in Korean.