# Callbacks and events

[Callbacks](cbev_callback) are used to handle requests from the remote system and return a user defined result (eg an alarm has been received and a response is required).
[Events](cbev_event) can notify the implementation about something that occurred (eg the hsms connection was selected). Events don\'t return any result to the remote and are executed in the background

```{toctree}
cbev_callback
cbev_event
```