at the same time
This expression is used when two or more actions occur simultaneously or when two or more states of affairs or situations exist together.
2. When this expression is used in the sense of (2) above, the subjects of the preceding and following clauses must be the same. The subject must occur once in the preceding clause.
In addition, it can be replaced with -(으)면서 with no major change in meaning. However, -(으)며 has a more literary nuance than -(으)면서.
Indicates that two or more actions are happening at the same time.