What does 交流 (jiāo liú) mean in English?

Card 210HSK 2010 Level 4210/586
CARD210
PROGRESS36%
交流
jiāo liú
exchange; give-and-take; to exchange; to alternate; communication; alternating current (electricity)

Reveal: Click/Space/Enter/↑↓/w/s/j/kNavigate: ←→/h/l/a/d