CSyncEvent class provides a mechanism which processes can use to synchronize access to a resource. This is very useful when you for example use shared memory for communication between processes.
Normally, if you want to know if a shared resource was accessed by another process and something was written into it, you would have to check the resource constantly. However, this method is inefficient. When using synchronization functions, like events, you just simply set the event state to signaled, this way other processes see it and instantly understand that something was written into a resource.