Anyone can tell me how fire alarm system work (basic or advance)?

Answer 1

Simple defition:

A system of connected devices for sensing fire and alerting occupants of a fire condition.

Advanced:

A system of initiating and indicating devices generally controlled from a single control panel through a network of supervised wiring. The panel may or may not report off site or to other annunciation equipement.

Initiating devices can include, but are not limited to, manual pull stations, various types of smoke and heat detectors, and can also include flame, spark, or ember detection and some even have gas detection, although the latter of those is not genrally required by code.

Indicating devices are generally horns & strobes, bells, chimes, or even speakers on voice systems. Voice systems also often include paging abilities.

Obviously in the event the initiating devices sense an alarm condition, then the indicating devices are activated.

That's about it.

I hope that answers your question.