Photon C++ Client API 22.214.171.124
Unlike operations, events are "messages" that are rarely triggered by the client that receives them. Events usually come from outside: the server or other clients.
They are created as a side effect of operations (e.g. when you join a room) or raised as main purpose of the operation (like done by opRaiseEvent()). Most events carry some form of data, but in rare cases the type of the event itself is the only message.
Events are instances of EventData with arbitrary content.