Difference between silences

Can anyone let me know the differences in silencing between these two URLs?

https://xxx.grafana.net/alerting/silences
https://xxx.grafana.net/a/grafana-alerting-ui-app/

and how do I know which version of Grafana I’m using?

Hi there!

The first Silences link will be used to silence any “Grafana Managed Alerts” which will be the panel based alerts. You’ll see panel based alerts referred to as legacy alerts or classic alerts.

The second link there will be used to silence any “Cortex/Loki Managed Alerts” which will be the Alertmanager style alerts.

There are some further details about the differences between these alert types in this other Community forum post.

There are also more docs for these two different alert types here:

Which type of alerting you use will just depend on your datasource and what conditions you are interested in alerting on. If you are shipping data to Grafana Cloud and want to alert based on the hosted metrics, logs, and/or traces then you’ll likely use the Cortex/Loki managed alert rules. If you have a directly connected datasource and you are visualizing data in place, you’ll likely use the Grafana managed alert rule (for those panel based alerts).

And to find out the version of Grafana that your instance is currently running, hover your mouse over the question mark at the bottom left corner. You should see something like this: