Smoke detectors are used as early warning systems for detecting smoke. Most smoke detectors have their own inbuilt pre-warning and if there is enough smoke detected, the main alarm system will be activated.
If you are monitored, the monitoring centre receives a signal from your alarm and will act as per your monitoring instructions.
There are two types of smoke detectors: Battery backup and non-battery backup. Both are powered by the alarm system. Generally, non-battery backup smoke detectors are used in commercial properties.
Thermal detectors are used for detecting heat. These are generally used in kitchens and laundries, where there are appliances that could cause there to be smoke, such as a toaster.
There are various types of thermal detectors: Fixed temperature or rate of rise.
Thermal detectors can have either of these options or both together.