교환하다(gyo-hwan-ha-da, gyohwanhada)
Active act of exchanging items or services by the subject
When to use
Direct exchange request, Active item exchange, Seller-buyer conversation
The nuance
Use when the subject actively performs the exchange. That is, when someone directly exchanges or requests to exchange an item.
교환되다(gyo-hwan-doe-da, gyohwandoeda)
Indicates the exchange act happened passively or was done to the subject
When to use
Passive exchange situation, Describing completed exchange, Item being the exchange target
The nuance
Use when the exchange is done by someone else or the subject is passively affected by the exchange.