1.
over there, the other side
A place that is across from or on the opposite side from where the speaker is.
2.
the opposite party, they
The other side in a negotiation or relationship.
向こう indicates a place across from or opposite the speaker's position. It implies there's something (like a road, river, or distance) between the speaker and that place. [noun]の向こう means 'on the other side of [noun].' It can also refer to 'them' or 'the other party' in business or relationship contexts.