Both parties or both sides; referring to the two parties involved in negotiations, discussions, or a situation.
交渉は双方の合意により終了した。
The negotiations ended by mutual agreement of both parties.
双方の立場を理解することが重要だ。
It's important to understand both sides' positions.
この取り決めは双方にとって有益だ。
This arrangement is beneficial to both parties.