Both Parties
Both Sides, Mutual
noun, の adjective
You've got a pair of directions, so this is something that concerns both parties or both sides. Things are going in two directions, not just one!
双方 is a relatively formal term that is often used in contexts like mutual agreements, negotiations, or discussions where both sides are actively engaged.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
片方だけでなく、双方の意見が知りたいですね。
I'd like to know the opinions of both sides, not just one.
結婚には双方の合意が必要です。
Marriage requires the consent of both parties.
双方の主張は平行線をたどっています。
Both sides' claims are no closer to being reconciled.