에 is the locative particle, and indicates either the direction someone is moving in, or the location of a noun. 에서 is used to indicate the location of an action. It is nearly identical to the Japanese particles に and へ, though usage varies slightly.

• 제 남자친구가 극장에 있어요 My boyfriend is in the theater.
• 네가 안양에 가요 I'm going to Anyang.
• 우리 아빠 회사 다녀요 My father works in a company.

[edit] See also

• 100 Basic Korean Words
• -에서