-(으)ㄴ/는 반면에 — whereas, on the other hand

This expression is used to express the fact that two things are opposites.

It can also be used to state both the positive and negative characteristics of something together in the same sentence.

It can be used with the particle 에 or in the form -(으)ㄴ/는 반면.

Details

When the preceding and following clauses represent opposites, the form -(으)ㄴ/는 데 반해 can also be used.

그 집은 비싼 데 반해 주변 환경은 별로 안 좋은 것 같습니다.

That house is expensive, but on the other hand, the surrounding environment doesn't look very good.

요줌 수입은 증가하는 데 반해 수출은 감소하고 있습니다.

In contrast to the recent increase in imports, exports are decreasing.

Used to show that two clauses are contrasting or opposite to each other.