What is the difference between alarm and siren?

An alarm is derived from the Greek "Alarmius", which means "to call or signal", and is the message itself.

The Word "siren" is, in stark contrast, derived from the name of the Latvian princess in the 1200s, Princess Sirenius. The shrill tone of her complaints became ubiquitous in Latvian folklore. It is the sound that conveys the message.

Thank you friend, I hope to see you in another life.