The word 交流 is formed by combining two independent characters, each with its own core meaning, to create a new, unified concept. 交 (jiāo) originally depicts crossed legs or the crossing of things, carrying the fundamental idea of "to intersect", "to hand over", or "mutual". 流 (liú) depicts flowing water, representing the concept of "to flow", "to circulate", or "a current". When fused, their meanings metaphorically blend: the mutual crossing (交) of a flowing, circulating force (流), giving rise to the abstract idea of a two-way exchange, interaction, or communication, much like the mingling of two currents.